The heat sensitivity of Human gingival squamous carcinoma Ca9-22 cells with oncogene erbB-1/EGFR and Chinese hamster V79 cells of normal thermosensitivity as control was investigated.Colony forming ability of the trea...The heat sensitivity of Human gingival squamous carcinoma Ca9-22 cells with oncogene erbB-1/EGFR and Chinese hamster V79 cells of normal thermosensitivity as control was investigated.Colony forming ability of the treated cells was assayed in vitro. Heat-treatment period-survival and the concerned curves were drawn.The slopes of exponentially regressing parts of the survival curves were estimated in the TO values of cellular thermosensitivity and subjected to Arrhenius analysis-The 42-44℃ time-survival curves of Ca9-22 cells showed biphasic slopes which indicated the presence of thermotolerance induction during continuous heating even at 44℃ while for the V79 cells the biphasic slopes due to thermotolerance induction were shown in temperatures at and before 42℃. In comparison of TO values with V79 cells, those of Ca9-22 cells were longer (less thermosensitive) by about 2.1 fold at 43℃ and 1-2 fold at 44℃. Both V79 and Ca9-22 cells were sensitized by 44--42℃ step-down heating (SDH).42℃ beat treatment period-survival curves of 44℃ ( 5minute) preheated V79 cells; while Ca9-22 cells under the same treatment condition for not only 5 minutes but 20 minutes showed biphasic slope, which indicated the Presence of thermotolerance. The thermosensitization ratio (TSR) of Ca9-22 cells were smaller than V79 cells.Arrhenius curves a breaking points at 44℃ and 43℃ for Ca9-22 and V79 cells, respectively. The activation energies of V79 cells were 145kcallmole and 400kcal/mole above and below 43℃ (p < 0.05), respectively,while those of Ca9-22 cells were 200 kcal/mole and 250kcal/mole above and below 44℃ (P <0.05), respectively.These data suggested that oncogene erbB-1 /EGFRcontained in Ca9-22 cells may contribute to reducethermosensitivity and variety in term of G￣1 phase as shown in fractionated Hydroxyurea treatment.展开更多
Novel complex hydrogels of methylcellulose （MC） and poly（vinyl alcohol） （PVA） with wide-spectrum thermoresponsivity were prepared via physical and mild process. Thermal phase transition of MC/PVA hydrogels exhib...Novel complex hydrogels of methylcellulose （MC） and poly（vinyl alcohol） （PVA） with wide-spectrum thermoresponsivity were prepared via physical and mild process. Thermal phase transition of MC/PVA hydrogels exhibited two forms including sol/sol to gel/sol and sol/gel to gel/gel. The phase transition temperature of MC/PVA solution ranged from 38,7 to 60.6 ℃ and was able to be adjusted by simply changing the feeding ratios of two components. The interior morphology of MC/PVA gels was examined with fluorescence analysis and scanning electron microscopy analysis, which showed that MC was well dispersed in matrix before and after thermally gelling.展开更多
Controlled polymerization of N-n-propylacrylamide was achieved by atom transfer radical polymerization(ATRP) in a N,N-dimethylformamide-water mixture(50 vol%)at room temperature with methyl 2-chloropropinonate as init...Controlled polymerization of N-n-propylacrylamide was achieved by atom transfer radical polymerization(ATRP) in a N,N-dimethylformamide-water mixture(50 vol%)at room temperature with methyl 2-chloropropinonate as initiator and CuCl/tris(2-dimethylaminoethyl)amine as the catalytic system in a ratio of 1:1:1.High molecular weight homopolymers(up to 3.7×10~4)with narrow molecular weight distribution(less than 1.2)were obtained.The living character of the polymerization was further demonstrated by self-blocking...展开更多
Up to date,solid-state carbon dots(CDs)with bright red fluorescence have scarcely achieved due to aggregation-caused quenching(ACQ)effect and extremely low quantum yield in deep-red to near infrared region.Here,we rep...Up to date,solid-state carbon dots(CDs)with bright red fluorescence have scarcely achieved due to aggregation-caused quenching(ACQ)effect and extremely low quantum yield in deep-red to near infrared region.Here,we report a novel fluorine-defects induced solid-state red fluorescence(λ_(em)=676 nm,the absolute fluorescence quantum yields is 4.17%)in fluorine,nitrogen and sulfur co-doped CDs(F,N,S-CDs),which is the first report of such a long wavelength emission of solid-state CDs.As a control,CDs without fluorine-doping(N,S-CDs)show no fluorescence in solid-state,and the fluorescence quantum yield/emission wavelength of N,S-CDs in solution-state are also lower/shorter than that of F,N,S-CDs,which is mainly due to the F-induced defect traps on the surface/edge of F,N,S-CDs.Moreover,the solid-state F,N,S-CDs exhibit an interesting temperature-sensitive behavior in the range of 80-420 K,with the maximum fluorescence intensity at 120 K,unveiling its potential as the temperature-dependent fluorescent sensor and the solid-state light-emitting device adapted to multiple temperatures.展开更多
Precision therapy has become the preferred choice attributed to the optimal drug concentration in target sites,increased therapeutic efficacy,and reduced adverse effects.Over the past few years,sprayable or injectable...Precision therapy has become the preferred choice attributed to the optimal drug concentration in target sites,increased therapeutic efficacy,and reduced adverse effects.Over the past few years,sprayable or injectable thermosensitive hydrogels have exhibited high therapeutic potential.These can be applied as cell-growing scaffolds or drug-releasing reservoirs by simply mixing in a free-flowing sol phase at room temperature.Inspired by their unique properties,thermosensitive hydrogels have been widely applied as drug delivery and treatment platforms for precision medicine.In this review,the state-of-theart developments in thermosensitive hydrogels for precision therapy are investigated,which covers from the thermo-gelling mechanisms and main components to biomedical applications,including wound healing,anti-tumor activity,osteogenesis,and periodontal,sinonasal and ophthalmic diseases.The most promising applications and trends of thermosensitive hydrogels for precision therapy are also discussed in light of their unique features.展开更多
Neurotrophic keratopathy is a persistent defect of the corneal epithelium,with or without stromal ulceration,due to corneal nerve deficiency caused by a variety of etiologies.The treatment options for neurotrophic ker...Neurotrophic keratopathy is a persistent defect of the corneal epithelium,with or without stromal ulceration,due to corneal nerve deficiency caused by a variety of etiologies.The treatment options for neurotrophic keratopathy are limited.In this study,an ophthalmic solution was constructed from a chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor(CTH-mNGF).Its effectiveness was evaluated in corneal denervation(CD)mice and patients with neurotrophic keratopathy.In the preclinical setting,CTH-mNGF was assessed in a murine corneal denervation model.CTH-mNGF was transparent,thermosensitive,and ensured sustained release of mNGF for over 20 hours on the ocular surface,maintaining the local mNGF concentration around 1300 pg/mL in vivo.Corneal denervation mice treated with CTH-mNGF for 10 days showed a significant increase in corneal nerve area and total corneal nerve length compared with non-treated and CTH treated mice.A subsequent clinical trial of CTH-mNGF was conducted in patients with stage 2 or 3 neurotrophic keratopathy.Patients received topical CTH-mNGF twice daily for 8 weeks.Fluorescein sodium images,Schirmer’s test,intraocular pressure,Cochet-Bonnet corneal perception test,and best corrected visual acuity were evaluated.In total,six patients(total of seven eyes)diagnosed with neurotrophic keratopathy were enrolled.After 8 weeks of CTH-mNGF treatment,all participants showed a decreased area of corneal epithelial defect,as stained by fluorescence.Overall,six out of seven eyes had fluorescence staining scores<5.Moreover,best corrected visual acuity,intraocular pressure,Schirmer’s test and Cochet-Bonnet corneal perception test results showed no significant improvement.An increase in corneal nerve density was observed by in vivo confocal microscopy after 8 weeks of CTH-mNGF treatment in three out of seven eyes.This study demonstrates that CTH-mNGF is transparent,thermosensitive,and has sustained-release properties.Its effectiveness in healing corneal epithelial defects in all eyes with neurotrophic keratopathy suggests CTH-mNGF has promising application prospects in the treatment of neurotrophic keratopathy,being convenient and cost effective.展开更多
Amultifunctional liposomal polydopamine nanoparticle(MPM@Lipo)was designed in this study,to combine chemotherapy,photothermal therapy(PTT)and oxygen enrichment to clear hyperproliferating inflammatory cells and improv...Amultifunctional liposomal polydopamine nanoparticle(MPM@Lipo)was designed in this study,to combine chemotherapy,photothermal therapy(PTT)and oxygen enrichment to clear hyperproliferating inflammatory cells and improve the hypoxic microenvironment for rheumatoid arthritis(RA)treatment.MPM@Lipo significantly scavenged intracellular reactive oxygen species and relieved joint hypoxia,thus contributing to the repolarization of M1 macrophages into M2 phenotype.Furthermore,MPM@Lipo could accumulate at inflammatory joints,inhibit the production of inflammatory factors,and protect cartilage in vivo,effectively alleviating RA progression in a rat adjuvant-induced arthritis model.Moreover,upon laser irradiation,MPM@Lipo can elevate the temperature to not only significantly obliterate excessively proliferating inflammatory cells but also accelerate the production of methotrexate and oxygen,resulting in excellent RA treatment effects.Overall,the use of synergistic chemotherapy/PTT/oxygen enrichment therapy to treat RA is a powerful potential strategy.展开更多
The lower critical solution temperature （LCST） behavior of poly（acrylamide-co-diacetone acrylamide） （poly（AM-co-DAM）） copolymer in aqueous solutions was studied. The results demonstrate the LCST linearly decre...The lower critical solution temperature （LCST） behavior of poly（acrylamide-co-diacetone acrylamide） （poly（AM-co-DAM）） copolymer in aqueous solutions was studied. The results demonstrate the LCST linearly decreases as the molar fraction of DAM （fDAM） increases. In the range of fDAM 〈 0.36, the transmittance increases as fDAM decreases because the more hydrophilic copolymer chains can form looser aggregates with a lower refractive index. The transmittance exhibits a minimum when fDAM is less than 0.28 as the chains form micelle-like structure with a size smaller than the wavelength. The LCST decreases with the initial polymer concentration, but it levels off when the polymer concentration is high enough. Moreover, no hysteresis can be observed in the change of transmittance during the heating-cooling process because no additional hydrogen bonds are formed in the collapsed state due to the steric hindrance of the large side groups in DAM units.展开更多
This pilot study reports the vertical transmission and reverse thermosensitivity of the MS-H vaccine strain of Mycoplasma synoviae (MS) by RAPD in commercial breeders and their progeny. At two weeks of age, breeders w...This pilot study reports the vertical transmission and reverse thermosensitivity of the MS-H vaccine strain of Mycoplasma synoviae (MS) by RAPD in commercial breeders and their progeny. At two weeks of age, breeders were vaccinated with the ts<sup>+</sup> MS-H strain. At 9 weeks of age, an outbreak of infectious synovitis (IS) was detected in the progeny. Tracheal swab samples were collected from breeders at 24, 39, 48, and 70 weeks of age. At 9 weeks, pullets swab from the elbow joints were collected. RAPD was performed on the isolates at 39.5°C, and the same ts<sup>-</sup> MS-H strains were identified in the breeder hens and their progeny. Tracheal swabs from breeder hens were negative to MS isolation at 37°C and 39.5°C at 24- and 39-weeks. MS isolation was recovered from tracheal swabs from 9/10 and 10/10 breeders at 48- and 70- week. At 9 weeks of age in the progeny, MS was isolated from tracheal swabs of 10/10 from non-IS pullets. MS was isolated from 9/10 joints samples. The isolates from breeder hens and their progeny showed non-significant differences in five antimycoplasmic MIC100 values;otherwise, enrofloxacin presented a significant difference in MIC100 value (p < 0.05). This investigation demonstrated the reversal of the thermosensitivity, pathogenicity, and vertical transmission of the MS-H strain. Consequently, it is crucial to contemplate the danger of reversing pathogenicity and transmission to progeny when applying the MS-H vaccine strain.展开更多
In this study, we reported the repaid construction of a molecular marker linkage map of rice (Oryza sativa L.). An F-2 population from the cross between Annong S-1 and Nanjing 11 was used to construct a genetic linkag...In this study, we reported the repaid construction of a molecular marker linkage map of rice (Oryza sativa L.). An F-2 population from the cross between Annong S-1 and Nanjing 11 was used to construct a genetic linkage map of rice. Total of 142 newly screened AFLP markers and 30 anchor markers (25 SSR markers and 5 RFLP markers) were mapped on the 12 chromosomes covering 1537.4 cM of rice genome. The average interval between these markers was 9.0 cM. The total work which usually was finished in more than one year was finished within only 3 months by one person. This is the first plant AFLP map developed in China. A new thermosensitive genic male sterile gene in rice, tms5, was Egged and mapped onto chromosome 2 during the development of the linkage map.展开更多
Aim To develop pluronic F127 （PF127） based formulations of penciclovir （PCV） aimed at enhancing its ocular bioavailability. Methods Thermosensitive in situ gels of penciclovir were prepared through combination of ...Aim To develop pluronic F127 （PF127） based formulations of penciclovir （PCV） aimed at enhancing its ocular bioavailability. Methods Thermosensitive in situ gels of penciclovir were prepared through combination of HPMC K4M or carbopol 934P and pluronic F127. Optimized formulations were examined through measuring gelation temperature, rheology speciality, drug release behavior, pharmacokinetics and ocular irritation. Results The gelation temperature was reduced by adding HPMC K4M or carbopol 934P, and the viscosity was enhanced slightly. Either HPMC K4M or carbopol 934P delayed the release of PCV from in situ gel. PCV was released by non-Fickian diffusion. The study of ocular irritation for different PCV formulations did not show any irritation or damage for the cornea. PCV bioavailability from combination of carbopol 934P and pluronic F127 gels was higher than that obtained from any other gels. Conclusion Pluronic F127 formulations of PCV can be used as liquid for administration by instilling into the eye. Facilitated by the appropriate eye temperature, the formulations were transformed to gel phase. On the basis of in vitro and in vivo results, PCV formulations containing HPMC K4M or carbopol 934P and low concentration of pluronic F127 （12%） showed potential for use as a drug delivery system with improved ocular bioavailability.展开更多
Adenine phosphoribosyltransferase (APRT) is the major enzyme that converts adenine into adenosine-3'-phosphate (AMP). APRT-deficient mutant caused by APRT gene mutation results in the male sterility in Arabidopsis...Adenine phosphoribosyltransferase (APRT) is the major enzyme that converts adenine into adenosine-3'-phosphate (AMP). APRT-deficient mutant caused by APRT gene mutation results in the male sterility in Arabidopsis thaliana L. In order to confirm the existence of rice APRT gene and to investigate its association with thermo-sensitive genic male sterile (TGMS) phenotype of rice, a APRT gene was identified from BLAST search of the rice genome database using APRT gene sequences from other plant species as probes. Further, the gene was cloned from rice and named APRT(GenBank accession number AY238894) using the combination of bioinformatic and experimental approaches. The rice APRT was located in the 56 000 bp to 63 000 bp region of a rice bacterial artificial chromosome (BAC) clone (AL606604) on chromosome 4 and was deduced by software from the positive DNA clone. Its cDNA was amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) using primers designed according to the sequence of the putative gene. The full-length cDNA was obtained by rapid amplification of cDNA ends (RACE) procedure and was sequenced. Open reading frame (ORF) analysis indicated that the rice APRT gene encodes a peptide of 212 amino acid residues, including seven exons and six introns. Using reverse position specific BLAST (RPS-BLAST), the APRT domain was identified in the polypeptide. The homology comparison demonstrated that the polypeptide exhibits 54.9%, 54.9%, 49.6% and 59.5% identity with that from Hordeum vulgare, Ttriticum aestivum, and A. thaliana (APRT types 1 and 2), respectively. Comparing the sequence of APRT gene from TGMS mutant lines 'Annong S-1' (Oryza sativa subsp. indica) with that from its corresponding wild type 'Annong F' (Oryza sativa. subsp. indica), we found that there are five single nucleotid polymorphism (SNP) sites in the gene of 'Annong S-1', which locate mainly in the second intron. However, the result of cDNA sequencing showed that these SNP sites do not damage the successful splicing of intron 2. Qualitative RT-PCR and Northern blot indicated that the gene tran-scription in the 'Annong S-1' young panicles that were verified to be the thermo-sensitive organ at the early stage of pollen fertility alternation is down-regulated by high temperature stress (28 V), which is the critical temperature causing 'Annong S-1' fertility conversion. These results revealed that the change of expression pattern of APRT in young particles of 'Annong S-1' in high temperature conditions is perhaps related to the TGMS of 'Annong S-1'.展开更多
Novel colloidal processing using thermosensitive poly（N-isopropylacrylamide） （PNIPAM） as a coagulating agent has beendeveloped to prepare complex-shaped ceramic components. In this work, the properties of PNIPAM a...Novel colloidal processing using thermosensitive poly（N-isopropylacrylamide） （PNIPAM） as a coagulating agent has beendeveloped to prepare complex-shaped ceramic components. In this work, the properties of PNIPAM aqueous solutions and therheological behavior of ZnO suspensions with PNIPAM were investigated. The results show that the PNIPAM solutions exhibitobvious thermosensitivity and its transition temperature is around 32℃. When the temperature is above 40℃ （Tc, the criticaltransition temperature of thermosensitive suspension）, the 50% ZnO （volume fraction） suspension with 8 mg/mL PNIPAM has asharp increase in viscosity and reaches up to 11.49 Pa·s at 50℃, displaying strong elasticity. The main reasons are the increase ofeffective volume fraction attributed to precipitation of PNIPAM segments and the flocculation between ZnO powder particles. Inaddition, the maximum solid loading （volume fraction） at 20 ℃ is higher than that at 40℃, which proves that the phase transition ofPNIPAM can induce the flocculation of suspension.展开更多
Global warming threatens food security.Rice(Oryza sativa L.),a vital food crop,is vulnerable to heat stress,especially at the reproductive stage.Here we summarize putative mechanisms of high-temperature perception(via...Global warming threatens food security.Rice(Oryza sativa L.),a vital food crop,is vulnerable to heat stress,especially at the reproductive stage.Here we summarize putative mechanisms of high-temperature perception(via RNA secondary structure,the phyB gene,and phase separation)and response(membrane fluidity,heat shock factors,heat shock proteins,and ROS(reactive oxygen species)scavenging)in plants.We describe how rice responds to heat stress at different cell-component levels(membrane,endoplasmic reticulum,chloroplasts,and mitochondria)and functional levels(denatured protein elimination,ROS scavenging,stabilization of DNA and RNA,translation,and metabolic flux changes).We list temperature-sensitive genetic male sterility loci available for use in rice hybrid breeding and explain the regulatory mechanisms associated with some of them.Breeding thermotolerant rice species without yield penalties via natural alleles mining and transgenic editing should be the focus of future work.展开更多
Novel thermosensitive hydrogels based on polymerization of N-isopropyl acrylamide, Sodium acrylate, and diacetone acrylamide were synthesized. The swelling ratio and dynamic swelling were investigated. The results ind...Novel thermosensitive hydrogels based on polymerization of N-isopropyl acrylamide, Sodium acrylate, and diacetone acrylamide were synthesized. The swelling ratio and dynamic swelling were investigated. The results indicated that the hydrogels exhibited high water uptake and themosensitivity. The swelling properties and volume phase transition temperature could be adjusted by contents of the comonomers in the gels.展开更多
The chitosan/β-glycerophosphate( CS/β-GP),a physical hydrogel system with thermosensitive and injectable features combined with biocompatibility and biodegradability, has great potentials as matrices for drug or cel...The chitosan/β-glycerophosphate( CS/β-GP),a physical hydrogel system with thermosensitive and injectable features combined with biocompatibility and biodegradability, has great potentials as matrices for drug or cell encapsulation and delivery,or as in situ gel-forming materials for tissue repair. Here,the chitin nanocrystal( Chi NC) was introduced into the aforementioned system, and its effects on solution behavior and mechanical properties was investigated. The results showed the incorporation of Chi NC complicated sol-to-gel transition process; a higher loading ratio( 20%) speeded up sol-to-gel transition rate,reduced the solto-gel transition temperature,while still maintained shear-thinning behavior or injectable feature. Moreover,the mechanical properties of gels were significantly enhanced by Chi NC, accompanied by decreased water uptake. The above mentioned behavior favored better applications as injectable tissue-repair implants.展开更多
In this study, the effect of silica/calcium phosphate (SiCaP) nanocomposite particles on the properties of a novel chitosan-based thermosensitive hydrogel system was examined. SiCaP nanocomposite powder was fabricated...In this study, the effect of silica/calcium phosphate (SiCaP) nanocomposite particles on the properties of a novel chitosan-based thermosensitive hydrogel system was examined. SiCaP nanocomposite powder was fabricated using a sol-gel method and then used to fabricate nanocomposite hydrogels (Ch- <em>β</em>/7.5SiCaP and Ch-<em>β</em>/15SiCaP) including chitosan and <em>β</em>-glycerophosphate (Ch-<em>β</em>) as a matrix. Results revealed that compared to the Ch-<em>β </em>hydrogel without SiCaP, the presence of SiCaP particles in nanocomposite hydrogels maintained pH stability during the sol-gel transition, accelerated the gelation and improved the stiffness of nanocomposite hydrogels. Gelation time at 37℃ was reduced approximately 75% and stiffness was increased approximately 115%. Both of these changes are attributed to chemical and physical interactions of the SiCaP bioactive particles with chitosan. Furthermore, compared to the Ch-<em>β</em> hydrogel, the presence of SiCaP in the Ch-<em>β</em>/7.5SiCaP nanocomposite hydrogel did not affect biocompatibility negatively, but improved osteoblastic cell differentiation. Our studies suggest that these nanocomposite hydrogels may offer an innovative approach to bone regeneration strategies.展开更多
Thermosensitive liposomes(TSLs) have been an important research area in the field of tumor targeted chemotherapy. Since the first TSLs appeared that using 1,2-dipalmitoyl-snglyce-ro-3-phosphocholine(DPPC) as the prima...Thermosensitive liposomes(TSLs) have been an important research area in the field of tumor targeted chemotherapy. Since the first TSLs appeared that using 1,2-dipalmitoyl-snglyce-ro-3-phosphocholine(DPPC) as the primary liposomal lipid, many studies have been done using this type of liposome from basic and practical aspects. While TSLs composed of DPPC enhance the cargo release near the phase transition temperature, it has been shown that many factors affect their temperature sensitivity. Thus numerous attempts have been undertaken to develop new TSLs for improving their thermal response performance. The main objective of this review is to introduce the development and recent update of innovative TSLs formulations, including combination of radiofrequency ablation(RFA), highintensity focused ultrasound(HIFU), magnetic resonance imaging(MRI) and alternating magnetic field(AMF). In addition, various factors affecting the design of TSLs, such as lipid composition, surfactant, size and serum components are also discussed.展开更多
Early-stage fire-warning systems(EFWSs)have attracted significant attention owing to their superiority in detecting fire situations occurring in the pre-combustion process.Substantial progress on EFWSs has been achiev...Early-stage fire-warning systems(EFWSs)have attracted significant attention owing to their superiority in detecting fire situations occurring in the pre-combustion process.Substantial progress on EFWSs has been achieved recently,and they have presented a considerable possibility for more evacuation time to control constant unintentional fire hazards in our daily life.This review mainly makes a comprehensive summary of the current EFWSs,including the working mechanisms and their performance.According to the different working mechanisms,fire alarms can be classified into graphene oxide-based fire alarms,semiconductor-based fire alarms,thermoelectric-based fire alarms,and fire alarms on other working mechanisms.Finally,the challenge and prospect for EFWSs are briefly provided by comparing the art of state of fire alarms.This work can propose a more comprehensive understanding of EFWSs and a guideline for the cutting-edge development direction of EFWSs for readers.展开更多
Long-terrn injectable microspheres have some inherent disadvantages such as migration of microspheres from the originalsite an.d the burst effect. In order to avoid these problems, microsphere-loaded thermosensitive, ...Long-terrn injectable microspheres have some inherent disadvantages such as migration of microspheres from the originalsite an.d the burst effect. In order to avoid these problems, microsphere-loaded thermosensitive, hydrogel system was designed and expected to achieve a zero-order release Of biomolecular drugs in relativehigh initial drug loadings. Lysozyme, an antibacterial protein usually used to reduce prosthetic valve endocarditis,was selected as the model drug. Poly （DL-lactide-co-glycolide） （PLGA） microspheres, prepared by solvent evaporation method, were employee to encapsulate lysozyme and dispersed into thermosensitive pre-gel solution containing methylcellulose （MC）, polyethylene glycol （PEG）, sodium citrate （SC）, and sodium alginate （SA）. The mixture could act asadrug reservoir by.performing sol-gel transition rapidly if the temperature was raised from roomtemperature to 37℃. The in vitro release results showed that the burst effect was avoided due to strengthening ofdiffusion resistance in the gel. The formulation was able.to deliver lysozy.me for over.30 daysin a nearly zero-order release profile with a rate of 32.8μg.d^-1 which exhibits its remarkable potential for effective aoolication in long-term drug delivery.展开更多
文摘The heat sensitivity of Human gingival squamous carcinoma Ca9-22 cells with oncogene erbB-1/EGFR and Chinese hamster V79 cells of normal thermosensitivity as control was investigated.Colony forming ability of the treated cells was assayed in vitro. Heat-treatment period-survival and the concerned curves were drawn.The slopes of exponentially regressing parts of the survival curves were estimated in the TO values of cellular thermosensitivity and subjected to Arrhenius analysis-The 42-44℃ time-survival curves of Ca9-22 cells showed biphasic slopes which indicated the presence of thermotolerance induction during continuous heating even at 44℃ while for the V79 cells the biphasic slopes due to thermotolerance induction were shown in temperatures at and before 42℃. In comparison of TO values with V79 cells, those of Ca9-22 cells were longer (less thermosensitive) by about 2.1 fold at 43℃ and 1-2 fold at 44℃. Both V79 and Ca9-22 cells were sensitized by 44--42℃ step-down heating (SDH).42℃ beat treatment period-survival curves of 44℃ ( 5minute) preheated V79 cells; while Ca9-22 cells under the same treatment condition for not only 5 minutes but 20 minutes showed biphasic slope, which indicated the Presence of thermotolerance. The thermosensitization ratio (TSR) of Ca9-22 cells were smaller than V79 cells.Arrhenius curves a breaking points at 44℃ and 43℃ for Ca9-22 and V79 cells, respectively. The activation energies of V79 cells were 145kcallmole and 400kcal/mole above and below 43℃ (p < 0.05), respectively,while those of Ca9-22 cells were 200 kcal/mole and 250kcal/mole above and below 44℃ (P <0.05), respectively.These data suggested that oncogene erbB-1 /EGFRcontained in Ca9-22 cells may contribute to reducethermosensitivity and variety in term of G￣1 phase as shown in fractionated Hydroxyurea treatment.
基金the support by Natural Science Foundation of Fujian Province of China(No.E0640005)for this project.
文摘Novel complex hydrogels of methylcellulose （MC） and poly（vinyl alcohol） （PVA） with wide-spectrum thermoresponsivity were prepared via physical and mild process. Thermal phase transition of MC/PVA hydrogels exhibited two forms including sol/sol to gel/sol and sol/gel to gel/gel. The phase transition temperature of MC/PVA solution ranged from 38,7 to 60.6 ℃ and was able to be adjusted by simply changing the feeding ratios of two components. The interior morphology of MC/PVA gels was examined with fluorescence analysis and scanning electron microscopy analysis, which showed that MC was well dispersed in matrix before and after thermally gelling.
基金This work was supported by the National Natural Science Foundation of China through Young Investigator Award(No.20328407)Nankai University,and the Canada Research Chair program.
文摘Controlled polymerization of N-n-propylacrylamide was achieved by atom transfer radical polymerization(ATRP) in a N,N-dimethylformamide-water mixture(50 vol%)at room temperature with methyl 2-chloropropinonate as initiator and CuCl/tris(2-dimethylaminoethyl)amine as the catalytic system in a ratio of 1:1:1.High molecular weight homopolymers(up to 3.7×10~4)with narrow molecular weight distribution(less than 1.2)were obtained.The living character of the polymerization was further demonstrated by self-blocking...
基金financially supported by the National Natural Science Foundation of China(No.51772001)Anhui Province Key Research and Development Plan Project International Science and Technology Cooperation Special Project(No.202004bll020015)support of the Key Laboratory of Structure and Functional Regulation of Hybrid Materials(Anhui University),Ministry of Education.
文摘Up to date,solid-state carbon dots(CDs)with bright red fluorescence have scarcely achieved due to aggregation-caused quenching(ACQ)effect and extremely low quantum yield in deep-red to near infrared region.Here,we report a novel fluorine-defects induced solid-state red fluorescence(λ_(em)=676 nm,the absolute fluorescence quantum yields is 4.17%)in fluorine,nitrogen and sulfur co-doped CDs(F,N,S-CDs),which is the first report of such a long wavelength emission of solid-state CDs.As a control,CDs without fluorine-doping(N,S-CDs)show no fluorescence in solid-state,and the fluorescence quantum yield/emission wavelength of N,S-CDs in solution-state are also lower/shorter than that of F,N,S-CDs,which is mainly due to the F-induced defect traps on the surface/edge of F,N,S-CDs.Moreover,the solid-state F,N,S-CDs exhibit an interesting temperature-sensitive behavior in the range of 80-420 K,with the maximum fluorescence intensity at 120 K,unveiling its potential as the temperature-dependent fluorescent sensor and the solid-state light-emitting device adapted to multiple temperatures.
基金financially supported by the National Natural Science Foundation of China(Grants 52172276)fund from Anhui Provincial Institute of Translational Medicine(2021zhyx-B15)。
文摘Precision therapy has become the preferred choice attributed to the optimal drug concentration in target sites,increased therapeutic efficacy,and reduced adverse effects.Over the past few years,sprayable or injectable thermosensitive hydrogels have exhibited high therapeutic potential.These can be applied as cell-growing scaffolds or drug-releasing reservoirs by simply mixing in a free-flowing sol phase at room temperature.Inspired by their unique properties,thermosensitive hydrogels have been widely applied as drug delivery and treatment platforms for precision medicine.In this review,the state-of-theart developments in thermosensitive hydrogels for precision therapy are investigated,which covers from the thermo-gelling mechanisms and main components to biomedical applications,including wound healing,anti-tumor activity,osteogenesis,and periodontal,sinonasal and ophthalmic diseases.The most promising applications and trends of thermosensitive hydrogels for precision therapy are also discussed in light of their unique features.
基金supported by PLA General Hospital Program,No.LB20201A010024(to LW).
文摘Neurotrophic keratopathy is a persistent defect of the corneal epithelium,with or without stromal ulceration,due to corneal nerve deficiency caused by a variety of etiologies.The treatment options for neurotrophic keratopathy are limited.In this study,an ophthalmic solution was constructed from a chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor(CTH-mNGF).Its effectiveness was evaluated in corneal denervation(CD)mice and patients with neurotrophic keratopathy.In the preclinical setting,CTH-mNGF was assessed in a murine corneal denervation model.CTH-mNGF was transparent,thermosensitive,and ensured sustained release of mNGF for over 20 hours on the ocular surface,maintaining the local mNGF concentration around 1300 pg/mL in vivo.Corneal denervation mice treated with CTH-mNGF for 10 days showed a significant increase in corneal nerve area and total corneal nerve length compared with non-treated and CTH treated mice.A subsequent clinical trial of CTH-mNGF was conducted in patients with stage 2 or 3 neurotrophic keratopathy.Patients received topical CTH-mNGF twice daily for 8 weeks.Fluorescein sodium images,Schirmer’s test,intraocular pressure,Cochet-Bonnet corneal perception test,and best corrected visual acuity were evaluated.In total,six patients(total of seven eyes)diagnosed with neurotrophic keratopathy were enrolled.After 8 weeks of CTH-mNGF treatment,all participants showed a decreased area of corneal epithelial defect,as stained by fluorescence.Overall,six out of seven eyes had fluorescence staining scores<5.Moreover,best corrected visual acuity,intraocular pressure,Schirmer’s test and Cochet-Bonnet corneal perception test results showed no significant improvement.An increase in corneal nerve density was observed by in vivo confocal microscopy after 8 weeks of CTH-mNGF treatment in three out of seven eyes.This study demonstrates that CTH-mNGF is transparent,thermosensitive,and has sustained-release properties.Its effectiveness in healing corneal epithelial defects in all eyes with neurotrophic keratopathy suggests CTH-mNGF has promising application prospects in the treatment of neurotrophic keratopathy,being convenient and cost effective.
文摘Amultifunctional liposomal polydopamine nanoparticle(MPM@Lipo)was designed in this study,to combine chemotherapy,photothermal therapy(PTT)and oxygen enrichment to clear hyperproliferating inflammatory cells and improve the hypoxic microenvironment for rheumatoid arthritis(RA)treatment.MPM@Lipo significantly scavenged intracellular reactive oxygen species and relieved joint hypoxia,thus contributing to the repolarization of M1 macrophages into M2 phenotype.Furthermore,MPM@Lipo could accumulate at inflammatory joints,inhibit the production of inflammatory factors,and protect cartilage in vivo,effectively alleviating RA progression in a rat adjuvant-induced arthritis model.Moreover,upon laser irradiation,MPM@Lipo can elevate the temperature to not only significantly obliterate excessively proliferating inflammatory cells but also accelerate the production of methotrexate and oxygen,resulting in excellent RA treatment effects.Overall,the use of synergistic chemotherapy/PTT/oxygen enrichment therapy to treat RA is a powerful potential strategy.
基金financially supported by the Ministry of Science and Technology of China(No.2012CB933802)the National Natural Science Foundation of China(Nos.21004057 and 21004058)
文摘The lower critical solution temperature （LCST） behavior of poly（acrylamide-co-diacetone acrylamide） （poly（AM-co-DAM）） copolymer in aqueous solutions was studied. The results demonstrate the LCST linearly decreases as the molar fraction of DAM （fDAM） increases. In the range of fDAM 〈 0.36, the transmittance increases as fDAM decreases because the more hydrophilic copolymer chains can form looser aggregates with a lower refractive index. The transmittance exhibits a minimum when fDAM is less than 0.28 as the chains form micelle-like structure with a size smaller than the wavelength. The LCST decreases with the initial polymer concentration, but it levels off when the polymer concentration is high enough. Moreover, no hysteresis can be observed in the change of transmittance during the heating-cooling process because no additional hydrogen bonds are formed in the collapsed state due to the steric hindrance of the large side groups in DAM units.
文摘This pilot study reports the vertical transmission and reverse thermosensitivity of the MS-H vaccine strain of Mycoplasma synoviae (MS) by RAPD in commercial breeders and their progeny. At two weeks of age, breeders were vaccinated with the ts<sup>+</sup> MS-H strain. At 9 weeks of age, an outbreak of infectious synovitis (IS) was detected in the progeny. Tracheal swab samples were collected from breeders at 24, 39, 48, and 70 weeks of age. At 9 weeks, pullets swab from the elbow joints were collected. RAPD was performed on the isolates at 39.5°C, and the same ts<sup>-</sup> MS-H strains were identified in the breeder hens and their progeny. Tracheal swabs from breeder hens were negative to MS isolation at 37°C and 39.5°C at 24- and 39-weeks. MS isolation was recovered from tracheal swabs from 9/10 and 10/10 breeders at 48- and 70- week. At 9 weeks of age in the progeny, MS was isolated from tracheal swabs of 10/10 from non-IS pullets. MS was isolated from 9/10 joints samples. The isolates from breeder hens and their progeny showed non-significant differences in five antimycoplasmic MIC100 values;otherwise, enrofloxacin presented a significant difference in MIC100 value (p < 0.05). This investigation demonstrated the reversal of the thermosensitivity, pathogenicity, and vertical transmission of the MS-H strain. Consequently, it is crucial to contemplate the danger of reversing pathogenicity and transmission to progeny when applying the MS-H vaccine strain.
文摘In this study, we reported the repaid construction of a molecular marker linkage map of rice (Oryza sativa L.). An F-2 population from the cross between Annong S-1 and Nanjing 11 was used to construct a genetic linkage map of rice. Total of 142 newly screened AFLP markers and 30 anchor markers (25 SSR markers and 5 RFLP markers) were mapped on the 12 chromosomes covering 1537.4 cM of rice genome. The average interval between these markers was 9.0 cM. The total work which usually was finished in more than one year was finished within only 3 months by one person. This is the first plant AFLP map developed in China. A new thermosensitive genic male sterile gene in rice, tms5, was Egged and mapped onto chromosome 2 during the development of the linkage map.
文摘Aim To develop pluronic F127 （PF127） based formulations of penciclovir （PCV） aimed at enhancing its ocular bioavailability. Methods Thermosensitive in situ gels of penciclovir were prepared through combination of HPMC K4M or carbopol 934P and pluronic F127. Optimized formulations were examined through measuring gelation temperature, rheology speciality, drug release behavior, pharmacokinetics and ocular irritation. Results The gelation temperature was reduced by adding HPMC K4M or carbopol 934P, and the viscosity was enhanced slightly. Either HPMC K4M or carbopol 934P delayed the release of PCV from in situ gel. PCV was released by non-Fickian diffusion. The study of ocular irritation for different PCV formulations did not show any irritation or damage for the cornea. PCV bioavailability from combination of carbopol 934P and pluronic F127 gels was higher than that obtained from any other gels. Conclusion Pluronic F127 formulations of PCV can be used as liquid for administration by instilling into the eye. Facilitated by the appropriate eye temperature, the formulations were transformed to gel phase. On the basis of in vitro and in vivo results, PCV formulations containing HPMC K4M or carbopol 934P and low concentration of pluronic F127 （12%） showed potential for use as a drug delivery system with improved ocular bioavailability.
文摘Adenine phosphoribosyltransferase (APRT) is the major enzyme that converts adenine into adenosine-3'-phosphate (AMP). APRT-deficient mutant caused by APRT gene mutation results in the male sterility in Arabidopsis thaliana L. In order to confirm the existence of rice APRT gene and to investigate its association with thermo-sensitive genic male sterile (TGMS) phenotype of rice, a APRT gene was identified from BLAST search of the rice genome database using APRT gene sequences from other plant species as probes. Further, the gene was cloned from rice and named APRT(GenBank accession number AY238894) using the combination of bioinformatic and experimental approaches. The rice APRT was located in the 56 000 bp to 63 000 bp region of a rice bacterial artificial chromosome (BAC) clone (AL606604) on chromosome 4 and was deduced by software from the positive DNA clone. Its cDNA was amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) using primers designed according to the sequence of the putative gene. The full-length cDNA was obtained by rapid amplification of cDNA ends (RACE) procedure and was sequenced. Open reading frame (ORF) analysis indicated that the rice APRT gene encodes a peptide of 212 amino acid residues, including seven exons and six introns. Using reverse position specific BLAST (RPS-BLAST), the APRT domain was identified in the polypeptide. The homology comparison demonstrated that the polypeptide exhibits 54.9%, 54.9%, 49.6% and 59.5% identity with that from Hordeum vulgare, Ttriticum aestivum, and A. thaliana (APRT types 1 and 2), respectively. Comparing the sequence of APRT gene from TGMS mutant lines 'Annong S-1' (Oryza sativa subsp. indica) with that from its corresponding wild type 'Annong F' (Oryza sativa. subsp. indica), we found that there are five single nucleotid polymorphism (SNP) sites in the gene of 'Annong S-1', which locate mainly in the second intron. However, the result of cDNA sequencing showed that these SNP sites do not damage the successful splicing of intron 2. Qualitative RT-PCR and Northern blot indicated that the gene tran-scription in the 'Annong S-1' young panicles that were verified to be the thermo-sensitive organ at the early stage of pollen fertility alternation is down-regulated by high temperature stress (28 V), which is the critical temperature causing 'Annong S-1' fertility conversion. These results revealed that the change of expression pattern of APRT in young particles of 'Annong S-1' in high temperature conditions is perhaps related to the TGMS of 'Annong S-1'.
基金Project(51202296)supported by the National Natural Science Foundation of ChinaProject(20120162120006)supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China
文摘Novel colloidal processing using thermosensitive poly（N-isopropylacrylamide） （PNIPAM） as a coagulating agent has beendeveloped to prepare complex-shaped ceramic components. In this work, the properties of PNIPAM aqueous solutions and therheological behavior of ZnO suspensions with PNIPAM were investigated. The results show that the PNIPAM solutions exhibitobvious thermosensitivity and its transition temperature is around 32℃. When the temperature is above 40℃ （Tc, the criticaltransition temperature of thermosensitive suspension）, the 50% ZnO （volume fraction） suspension with 8 mg/mL PNIPAM has asharp increase in viscosity and reaches up to 11.49 Pa·s at 50℃, displaying strong elasticity. The main reasons are the increase ofeffective volume fraction attributed to precipitation of PNIPAM segments and the flocculation between ZnO powder particles. Inaddition, the maximum solid loading （volume fraction） at 20 ℃ is higher than that at 40℃, which proves that the phase transition ofPNIPAM can induce the flocculation of suspension.
基金supported by the National Natural Science Foundation of China(31630052,31788103)Chinese Academy of Sciences(XDB27010104,QYZDYSSW-SMC023,159231KYSB20200008)+1 种基金the National Key Research and Development Program of China(2016YFD0100604)the Shanghai Science and Technology Development(18JC1415000)。
文摘Global warming threatens food security.Rice(Oryza sativa L.),a vital food crop,is vulnerable to heat stress,especially at the reproductive stage.Here we summarize putative mechanisms of high-temperature perception(via RNA secondary structure,the phyB gene,and phase separation)and response(membrane fluidity,heat shock factors,heat shock proteins,and ROS(reactive oxygen species)scavenging)in plants.We describe how rice responds to heat stress at different cell-component levels(membrane,endoplasmic reticulum,chloroplasts,and mitochondria)and functional levels(denatured protein elimination,ROS scavenging,stabilization of DNA and RNA,translation,and metabolic flux changes).We list temperature-sensitive genetic male sterility loci available for use in rice hybrid breeding and explain the regulatory mechanisms associated with some of them.Breeding thermotolerant rice species without yield penalties via natural alleles mining and transgenic editing should be the focus of future work.
文摘Novel thermosensitive hydrogels based on polymerization of N-isopropyl acrylamide, Sodium acrylate, and diacetone acrylamide were synthesized. The swelling ratio and dynamic swelling were investigated. The results indicated that the hydrogels exhibited high water uptake and themosensitivity. The swelling properties and volume phase transition temperature could be adjusted by contents of the comonomers in the gels.
基金National Natural Science Foundation of China(No.51303024)
文摘The chitosan/β-glycerophosphate( CS/β-GP),a physical hydrogel system with thermosensitive and injectable features combined with biocompatibility and biodegradability, has great potentials as matrices for drug or cell encapsulation and delivery,or as in situ gel-forming materials for tissue repair. Here,the chitin nanocrystal( Chi NC) was introduced into the aforementioned system, and its effects on solution behavior and mechanical properties was investigated. The results showed the incorporation of Chi NC complicated sol-to-gel transition process; a higher loading ratio( 20%) speeded up sol-to-gel transition rate,reduced the solto-gel transition temperature,while still maintained shear-thinning behavior or injectable feature. Moreover,the mechanical properties of gels were significantly enhanced by Chi NC, accompanied by decreased water uptake. The above mentioned behavior favored better applications as injectable tissue-repair implants.
文摘In this study, the effect of silica/calcium phosphate (SiCaP) nanocomposite particles on the properties of a novel chitosan-based thermosensitive hydrogel system was examined. SiCaP nanocomposite powder was fabricated using a sol-gel method and then used to fabricate nanocomposite hydrogels (Ch- <em>β</em>/7.5SiCaP and Ch-<em>β</em>/15SiCaP) including chitosan and <em>β</em>-glycerophosphate (Ch-<em>β</em>) as a matrix. Results revealed that compared to the Ch-<em>β </em>hydrogel without SiCaP, the presence of SiCaP particles in nanocomposite hydrogels maintained pH stability during the sol-gel transition, accelerated the gelation and improved the stiffness of nanocomposite hydrogels. Gelation time at 37℃ was reduced approximately 75% and stiffness was increased approximately 115%. Both of these changes are attributed to chemical and physical interactions of the SiCaP bioactive particles with chitosan. Furthermore, compared to the Ch-<em>β</em> hydrogel, the presence of SiCaP in the Ch-<em>β</em>/7.5SiCaP nanocomposite hydrogel did not affect biocompatibility negatively, but improved osteoblastic cell differentiation. Our studies suggest that these nanocomposite hydrogels may offer an innovative approach to bone regeneration strategies.
基金National Natural Science Foundation of China (No.31671020) for financial support
文摘Thermosensitive liposomes(TSLs) have been an important research area in the field of tumor targeted chemotherapy. Since the first TSLs appeared that using 1,2-dipalmitoyl-snglyce-ro-3-phosphocholine(DPPC) as the primary liposomal lipid, many studies have been done using this type of liposome from basic and practical aspects. While TSLs composed of DPPC enhance the cargo release near the phase transition temperature, it has been shown that many factors affect their temperature sensitivity. Thus numerous attempts have been undertaken to develop new TSLs for improving their thermal response performance. The main objective of this review is to introduce the development and recent update of innovative TSLs formulations, including combination of radiofrequency ablation(RFA), highintensity focused ultrasound(HIFU), magnetic resonance imaging(MRI) and alternating magnetic field(AMF). In addition, various factors affecting the design of TSLs, such as lipid composition, surfactant, size and serum components are also discussed.
基金This work was partially supported by the China Scholarship Council under the Grant CSC(201908110272)BIOFIRESAFE Project funded by Ministerio De Ciencia E Innovacion,Spain,with the project numbers:PID2020-117274RB-I00BIOFIRESAFE and PEJ-2018 MINECO.
文摘Early-stage fire-warning systems(EFWSs)have attracted significant attention owing to their superiority in detecting fire situations occurring in the pre-combustion process.Substantial progress on EFWSs has been achieved recently,and they have presented a considerable possibility for more evacuation time to control constant unintentional fire hazards in our daily life.This review mainly makes a comprehensive summary of the current EFWSs,including the working mechanisms and their performance.According to the different working mechanisms,fire alarms can be classified into graphene oxide-based fire alarms,semiconductor-based fire alarms,thermoelectric-based fire alarms,and fire alarms on other working mechanisms.Finally,the challenge and prospect for EFWSs are briefly provided by comparing the art of state of fire alarms.This work can propose a more comprehensive understanding of EFWSs and a guideline for the cutting-edge development direction of EFWSs for readers.
基金Supported by the National Natural Science Foundation of China （No.20576057） and Fundamental Research Foundation of Tsinghua University （JCqn2005033）.
文摘Long-terrn injectable microspheres have some inherent disadvantages such as migration of microspheres from the originalsite an.d the burst effect. In order to avoid these problems, microsphere-loaded thermosensitive, hydrogel system was designed and expected to achieve a zero-order release Of biomolecular drugs in relativehigh initial drug loadings. Lysozyme, an antibacterial protein usually used to reduce prosthetic valve endocarditis,was selected as the model drug. Poly （DL-lactide-co-glycolide） （PLGA） microspheres, prepared by solvent evaporation method, were employee to encapsulate lysozyme and dispersed into thermosensitive pre-gel solution containing methylcellulose （MC）, polyethylene glycol （PEG）, sodium citrate （SC）, and sodium alginate （SA）. The mixture could act asadrug reservoir by.performing sol-gel transition rapidly if the temperature was raised from roomtemperature to 37℃. The in vitro release results showed that the burst effect was avoided due to strengthening ofdiffusion resistance in the gel. The formulation was able.to deliver lysozy.me for over.30 daysin a nearly zero-order release profile with a rate of 32.8μg.d^-1 which exhibits its remarkable potential for effective aoolication in long-term drug delivery.
