Bacterial cellulose/polyacrylic acid (BC/PAA) pH-responsive hydrogels were prepared by free-radical polymerization (in situ) using BC as the raw material and AA as the monomer. The hydrogels were loaded with curcumin ...Bacterial cellulose/polyacrylic acid (BC/PAA) pH-responsive hydrogels were prepared by free-radical polymerization (in situ) using BC as the raw material and AA as the monomer. The hydrogels were loaded with curcumin (Cur) to prepare pH-responsive intelligent medical dressings. The preparation process of the hydrogels was optimized by a single factor and response surface experiment using their swelling degree as an index. The structures of BC/PAA pH-responsive hydrogels were characterized by scanning electron microscope (SEM), Fourier Transform Infrared spectrometer (FTIR), X-ray diffraction (XRD), and tensile tester, and the swelling properties, mechanical properties, bacteriostatic properties, and drug release behavior were investigated. The results showed that the BC/PAA pH-responsive hydrogel has a three-dimensional network structure with the swelling rate up to 1600 g/g, compressive strength of up to 8 KPa, and good mechanical properties, and the drug release behavior was in line with the logistic dynamics model, and it has good inhibitory effects on common pathogens of wound infection: E. coli, S. aureus, and P. aeruginosa.展开更多
Currently,it is a challenge to develop hemostatic materials with high water absorption capacity and anti-fatigue properties for quickly preventing massive hemorrhage from arteries and visceral organs.A series of polya...Currently,it is a challenge to develop hemostatic materials with high water absorption capacity and anti-fatigue properties for quickly preventing massive hemorrhage from arteries and visceral organs.A series of polyacrylic acid/chitosan(PAA/CS)cryogels were prepared by a cryostructurization technique to improve mechanical performance and hemostatic efficiency of chitosan(CS).In this system,the chemically cross-linked PAA network was used as a framework to improve water absorption behaviors and mechanical strength.The CS network was co-blended by hydrogen bonding and electrostatic interactions,both of which synergistically promoted hemostasis.These cryogels had high porosity(>94%),rapid water absorption rate(<3 s),high blood absorption capacity(>2000%),outstanding mechanical strength,and fatigue resistance.Moreover,the results of cytotoxicity and hemolysis demonstrated that the cryogels had good biocompatibility.Notably,the PAA/CS cryogels exhibited superior whole blood coagulation ability and red blood cell and platelet adhesion ability compared to those of commercial hemostatic dressing(gauze,gelatin sponges,and CS sponges).Based on these results,mouse femoral artery hemorrhage models and liver hemorrhage models were prepared to investigate the hemostatic ability of the prepared PAA/CS cryogels.Results suggested that the hemostatic ability of PAA5/CS cryogels was superior to that of commercial hemostatic materials.Therefore,the PAA/CS cryogels showed potential application in preventing massive hemorrhage from arteries and visceral organs.展开更多
Lanthanide-doped upconversion nanoparticles(Ln-UCNPs)are a new type of nanomaterials with excellent fluorescence properties,which are well applied in fluorescent biosensing.Herein we developed a multifunctional probe ...Lanthanide-doped upconversion nanoparticles(Ln-UCNPs)are a new type of nanomaterials with excellent fluorescence properties,which are well applied in fluorescent biosensing.Herein we developed a multifunctional probe based on the surface engineering of core-shell structure UCNPs with polyacrylic acid(PAA).The developed PAA/UCNPs probe could be highly selective to detect and respond to Cu^(2+) at different pH.Cu^(2+) could easily combine with the carboxylate anion of PAA to quench the fluorescence of UCNPs.Therefore,we creatively proposed a fluorescent array sensor(PAA/UCNPs-Cu^(2+)),in which the same material acted as the sensing element by coupled with pH regulation for pattern recognition of 5 thiols.It could also easily identify the chiral enantiomer of cystine(L-Cys-and D-Cys),and distinguish their mixed samples with different concentrations,and more importantly,it could be combined with urine samples to detect actual level of homocysteine(Hcys)to provide a new solution for judging whether the human body suffers from homocystinuria.展开更多
Andrographolide(AG)has favorable anti-inflammatory and antioxidative capacity.However,it has low bioavailability due to high lipophilicity and can be easily cleared by the synovial fluid after intra-articular injectio...Andrographolide(AG)has favorable anti-inflammatory and antioxidative capacity.However,it has low bioavailability due to high lipophilicity and can be easily cleared by the synovial fluid after intra-articular injection,leading to low therapeutic efficiency in osteoarthritis(OA).Herein,we designed a nano-sized pH-responsive drug delivery system(DDS)for OA treatment by using modified mesoporous silica nanoparticles(MSNs)with pH-responsive polyacrylic acid(PAA)for loading of AG to form AG@MSNs-PAA nanoplatform.The nanoparticles have uniform size(120 nm),high drug loading efficiency(22.3860.71%)and pH-responsive properties,beneficial to sustained release in OA environment.Compared with AG,AG@MSNs-PAA showed enhanced antiarthritic efficacy and chondro-protective capacity based on IL-1b-stimulated chondrocytes and anterior cruciate ligament transection-induced rat OA model,as demonstrated by lower expression of inflammatory factors and better prevention of proteoglycan loss.Therefore,the AG@MSNs-PAA nanoplatform may be developed as a promising OA-specific and on-demand DDS.展开更多
Recently,a de novo synthetic calcium-responsive self-assemblyβ-sheet peptide ID8(Ile-Asp-Ile-Asp-Ile-Asp-Ile-Asp)has been developed to serve as the template inducing hydroxyapatite nucleation.The aim of this study wa...Recently,a de novo synthetic calcium-responsive self-assemblyβ-sheet peptide ID8(Ile-Asp-Ile-Asp-Ile-Asp-Ile-Asp)has been developed to serve as the template inducing hydroxyapatite nucleation.The aim of this study was to evaluate the effect of ID8 on intrafibrillar mineralization of collagen making full use of its self-assembly ability.The mineralization experiments were carried out in vitro on both bare TypeⅠcollagen and fully demineralized dentin samples.The calcium-responsive self-assembly of ID8 was revealed by circular dichroism spectrum,8-anilino-1-naphthalenesulfonic acid ammonium salt hydrate assay,attenuated total reflection Fourier transform infrared spectrum(ATR-FTIR)and transmission electron microscope(TEM).Polyacrylic acid(450 kDa)with a concentration of 100μg ml^(-1)was selected as the nucleation inhibitor based on the determination of turbidimetry and TEM with selected area electron diffraction(TEM-SAED).The results showed that collagen intrafibrillar mineralization was significantly promoted with the pretreatment of self-assembly ID8 detected by TEM-SAED,SEM,X-ray diffraction and ATRFTIR.The pretreatment of collagen utilizing self-assembly ID8 not only enhanced intermolecular hydrogen bonding but also contributed to calcium retention inside collagen and significantly increased the hydrophilicity of collagen.These results indicated that peptides with self-assembly properties like ID8 are expected to be potential tools for biomimetic mineralization of collagen.展开更多
文摘Bacterial cellulose/polyacrylic acid (BC/PAA) pH-responsive hydrogels were prepared by free-radical polymerization (in situ) using BC as the raw material and AA as the monomer. The hydrogels were loaded with curcumin (Cur) to prepare pH-responsive intelligent medical dressings. The preparation process of the hydrogels was optimized by a single factor and response surface experiment using their swelling degree as an index. The structures of BC/PAA pH-responsive hydrogels were characterized by scanning electron microscope (SEM), Fourier Transform Infrared spectrometer (FTIR), X-ray diffraction (XRD), and tensile tester, and the swelling properties, mechanical properties, bacteriostatic properties, and drug release behavior were investigated. The results showed that the BC/PAA pH-responsive hydrogel has a three-dimensional network structure with the swelling rate up to 1600 g/g, compressive strength of up to 8 KPa, and good mechanical properties, and the drug release behavior was in line with the logistic dynamics model, and it has good inhibitory effects on common pathogens of wound infection: E. coli, S. aureus, and P. aeruginosa.
基金supported by the National Natural Science Foundation of China(Grant Nos.U20A20261,31870948,31971250,and 52073205)Natural Science Foundation of Tianjin(Grant No.20JCYBJC00660)。
文摘Currently,it is a challenge to develop hemostatic materials with high water absorption capacity and anti-fatigue properties for quickly preventing massive hemorrhage from arteries and visceral organs.A series of polyacrylic acid/chitosan(PAA/CS)cryogels were prepared by a cryostructurization technique to improve mechanical performance and hemostatic efficiency of chitosan(CS).In this system,the chemically cross-linked PAA network was used as a framework to improve water absorption behaviors and mechanical strength.The CS network was co-blended by hydrogen bonding and electrostatic interactions,both of which synergistically promoted hemostasis.These cryogels had high porosity(>94%),rapid water absorption rate(<3 s),high blood absorption capacity(>2000%),outstanding mechanical strength,and fatigue resistance.Moreover,the results of cytotoxicity and hemolysis demonstrated that the cryogels had good biocompatibility.Notably,the PAA/CS cryogels exhibited superior whole blood coagulation ability and red blood cell and platelet adhesion ability compared to those of commercial hemostatic dressing(gauze,gelatin sponges,and CS sponges).Based on these results,mouse femoral artery hemorrhage models and liver hemorrhage models were prepared to investigate the hemostatic ability of the prepared PAA/CS cryogels.Results suggested that the hemostatic ability of PAA5/CS cryogels was superior to that of commercial hemostatic materials.Therefore,the PAA/CS cryogels showed potential application in preventing massive hemorrhage from arteries and visceral organs.
基金supported by the National Natural Science Foundation of China(No.21775044)the Shanghai Science and Technology Committee(Nos.19ZR1473300 and 18DZ1112700)the Fundamental Research Funds for the Central Universities。
文摘Lanthanide-doped upconversion nanoparticles(Ln-UCNPs)are a new type of nanomaterials with excellent fluorescence properties,which are well applied in fluorescent biosensing.Herein we developed a multifunctional probe based on the surface engineering of core-shell structure UCNPs with polyacrylic acid(PAA).The developed PAA/UCNPs probe could be highly selective to detect and respond to Cu^(2+) at different pH.Cu^(2+) could easily combine with the carboxylate anion of PAA to quench the fluorescence of UCNPs.Therefore,we creatively proposed a fluorescent array sensor(PAA/UCNPs-Cu^(2+)),in which the same material acted as the sensing element by coupled with pH regulation for pattern recognition of 5 thiols.It could also easily identify the chiral enantiomer of cystine(L-Cys-and D-Cys),and distinguish their mixed samples with different concentrations,and more importantly,it could be combined with urine samples to detect actual level of homocysteine(Hcys)to provide a new solution for judging whether the human body suffers from homocystinuria.
基金This study was financially supported by The National key research and development program of China(2016YFB0700800)the National Natural Science Foundation of China(Grant No.81972120)the Guangxi Science and Technology Base and Talent Special Project(Grant No.GuikeAD19254003),the Seventh Batch of Special Experts in Guangxi(Professor Wei Yao).
文摘Andrographolide(AG)has favorable anti-inflammatory and antioxidative capacity.However,it has low bioavailability due to high lipophilicity and can be easily cleared by the synovial fluid after intra-articular injection,leading to low therapeutic efficiency in osteoarthritis(OA).Herein,we designed a nano-sized pH-responsive drug delivery system(DDS)for OA treatment by using modified mesoporous silica nanoparticles(MSNs)with pH-responsive polyacrylic acid(PAA)for loading of AG to form AG@MSNs-PAA nanoplatform.The nanoparticles have uniform size(120 nm),high drug loading efficiency(22.3860.71%)and pH-responsive properties,beneficial to sustained release in OA environment.Compared with AG,AG@MSNs-PAA showed enhanced antiarthritic efficacy and chondro-protective capacity based on IL-1b-stimulated chondrocytes and anterior cruciate ligament transection-induced rat OA model,as demonstrated by lower expression of inflammatory factors and better prevention of proteoglycan loss.Therefore,the AG@MSNs-PAA nanoplatform may be developed as a promising OA-specific and on-demand DDS.
基金supported by the National Natural Science Foundation of China(Grant Nos.81470734,Grant Nos.81970931).
文摘Recently,a de novo synthetic calcium-responsive self-assemblyβ-sheet peptide ID8(Ile-Asp-Ile-Asp-Ile-Asp-Ile-Asp)has been developed to serve as the template inducing hydroxyapatite nucleation.The aim of this study was to evaluate the effect of ID8 on intrafibrillar mineralization of collagen making full use of its self-assembly ability.The mineralization experiments were carried out in vitro on both bare TypeⅠcollagen and fully demineralized dentin samples.The calcium-responsive self-assembly of ID8 was revealed by circular dichroism spectrum,8-anilino-1-naphthalenesulfonic acid ammonium salt hydrate assay,attenuated total reflection Fourier transform infrared spectrum(ATR-FTIR)and transmission electron microscope(TEM).Polyacrylic acid(450 kDa)with a concentration of 100μg ml^(-1)was selected as the nucleation inhibitor based on the determination of turbidimetry and TEM with selected area electron diffraction(TEM-SAED).The results showed that collagen intrafibrillar mineralization was significantly promoted with the pretreatment of self-assembly ID8 detected by TEM-SAED,SEM,X-ray diffraction and ATRFTIR.The pretreatment of collagen utilizing self-assembly ID8 not only enhanced intermolecular hydrogen bonding but also contributed to calcium retention inside collagen and significantly increased the hydrophilicity of collagen.These results indicated that peptides with self-assembly properties like ID8 are expected to be potential tools for biomimetic mineralization of collagen.
