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1.
J Nanosci Nanotechnol ; 20(2): 719-730, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383067

RESUMO

The efficient removal of toxic metal ions from waste water is of critical importance in environmental protection. In this study, we report the incorporation of graphene oxide (GO) into bacterial cellulose (BC) and the effect on the removal of metal ions from waste water. The as-prepared BC/GO adsorbents have a three-dimensional (3D) network structure with interconnected pores and high porosity. The adsorption capacities and efficiencies of the BC/GO adsorbents with varying GO contents were compared by using Cu2+, Cd2+, and Pb2+ as model heavy metal ions. The incorporated GO into the BC/GO adsorbents plays a critical role in removing metal ions through strong electrostatic interactions between the positive metal ions and the negative functional groups on GO. In addition, the effects of pH, contact time, adsorbent dose, and ion concentration on the adsorption behavior of the BC/GO adsorbents were investigated. The data from adsorption kinetics indicate that the adsorption of Cu2+, Cd2+, and Pb2+ on BC/GO obeys a pseudo-second-order model, while the adsorption isotherms vary with the type of metal ions. The desorption and readsorption experiments of the BC/GO adsorbents demonstrate good recyclability. It has been demonstrated that incorporating GO into BC is an effective way to improve the adsorption behavior of BC.

2.
ACS Appl Mater Interfaces ; 11(23): 21184-21193, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31117467

RESUMO

Hydrogels based on supramolecular noncovalent interactions have attracted great research interest but are still limited by relatively low mechanical strength and performance deterioration at subzero temperatures because of the formation of ice crystallization. In this study, an antifreezing and mechanically strong gelatin supramolecular organohydrogel is prepared via a simple strategy of immersing a gelatin pre-hydrogel in the citrate (Cit) water/glycerol mixture solution. In the organohydrogel, a part of water molecules are replaced by glycerol, which inhibits the formation of ice crystallization even at extremely low temperature. In addition, the formation of noncovalent interactions such as the hydrophobic aggregation induced by the salting-out effect, ionic interactions between the -NH3+ of gelatin and Cit3- anions, and hydrogen bonding between gelatin chains and glycerol endows the organohydrogels with high mechanical strength and toughness. The supramolecular organohydrogel can maintain its mechanical flexibility even at -80 °C or be stored for a long time. Moreover, the nature of noncovalent interactions endows the organohydrogel with intriguing thermoplasticity, good healable ability, and excellent adhesive behavior at various substrate surfaces.

3.
Nanomicro Lett ; 10(3): 42, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30393691

RESUMO

Uniform dispersion of two-dimensional (2D) graphene materials in polymer matrices remains challenging. In this work, a novel layer-by-layer assembly strategy was developed to prepare a sophisticated nanostructure with highly dispersed 2D graphene oxide in a three-dimensional matrix consisting of one-dimensional bacterial cellulose (BC) nanofibers. This method is a breakthrough, with respect to the conventional static culture method for BC that involves multiple in situ layer-by-layer assembly steps at the interface between previously grown BC and the culture medium. In the as-prepared BC/GO nanocomposites, the GO nanosheets are mechanically bundled and chemically bonded with BC nanofibers via hydrogen bonding, forming an intriguing nanostructure. The sophisticated nanostructure of the BC/GO leads to greatly enhanced mechanical properties compared to those of bare BC. This strategy is versatile, facile, scalable, and can be promising for the development of high-performance BC-based nanocomposite hydrogels.

6.
Acta Biomater ; 74: 439-453, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29803006

RESUMO

Postoperative adhesions are very common complications after general abdominal surgery. Although adhesiolysis has been proven effective in eliminating the preexisting adhesions, the new trauma caused by surgical lysis can induce recurrent adhesion. The prevention of recurrent adhesion after adhesiolysis is more difficult because the injury is more severe and adhesion mechanism is more complicated compared with the primary adhesion. In this study, a thermoresponsive hydrogel contained galactose modified xyloglucan (mXG) and hydroxybutyl chitosan (HBC) was developed as a barrier device for recurrent adhesion prevention after adhesiolysis due to its injectability and spontaneous gelling behaviors at the body temperature without any chemical reactions or extra driving factors. First, mXG and HBC were synthesized via enzymatic modification and etherification reaction, respectively. Rheological measurements indicated that the mXG/HBC composite system showed excellent thermosensitivity properties, and their gelation temperature and time can be modulated via adjusting the mXG/HBC ratio. Moreover, the mXG/HBC hydrogel exhibited excellent cytocompatibility and hemocompatibility in vitro. Furthermore, the mXG/HBC hydrogel could promote wound healing in the rat skin wound model. Finally, the efficacy of the mXG/HBC composite hydrogel in the prevention of recurrent adhesion was evaluated in a more rigorous rat repeated-injury adhesion model. The results demonstrated that the composite hydrogel could not only effectively prevent recurrent adhesion after adhesiolysis, but also promote wound healing and reduce scare formation. These results suggested that the mXG/HBC composite hydrogel may be a promising candidate as an injectable anti-adhesion system for clinical applications. STATEMENT OF SIGNIFICANCE: Although adhesiolysis has been proven effective in eliminating the preexisting adhesions, the new trauma caused by surgical lysis can induce recurrent adhesion. So far, most of the existing barrier systems and pharmacological approaches were developed for primary adhesion prevention while few attention has paid on prevention of recurrent adhesion after adhesiolysis. In the present study, we developed a thermoresponsive polysaccharide-based composite hydrogel by simple mixing galactose modified xyloglucan (mXG) and hydroxybutyl chitosan (HBC). The resulting mXG/HBC composite hydrogel not only was easy to handle and highly effective in preventing the recurrent adhesion after adhesiolysis, but also could promote wound healing and reduce scare formation. Our study provide an effective anti-adhesion system for preventing recurrent adhesion after adhesiolysis.

7.
Biomaterials ; 157: 149-160, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29272722

RESUMO

Brown adipose derived stem cells (BADSCs) have become a promising stem cell treatment candidate for myocardial infarction because of their efficiently spontaneous differentiation capacity towards cardiomyocytes. The lack of existing cell passage protocols motivates us to develop a neotype 3D cell expansion technique for BADSCs. In this study, "clickable" zwitterionic starch based hydrogels are developed using methacrylate modified sulfobetaine derived starch with dithiol-functionalized poly (ethylene glycol) as crosslinker via the "thiol-ene" Michael addition reaction. Moreover, CGRGDS peptide is immobilized into the hydrogel via a similar "clickable" approach. Their Young's moduli range from 22.28 to 74.81 kPa depending on the concentration of precursor solutions. Excellent anti-fouling property is also presented owing to the introduction of zwitterionic moieties. BADSCs are homogeneously encapsulated in the hydrogels and then routinely cultured for 10 days. Results suggest a capacious cell proliferation and the extent increases with either the decrease of mechanical strength or the introduction of CGRGDS. More excitingly, the cell "stemness" is well maintained during this period and the expanded cells released from the hydrogels well keep the efficiently spontaneous cardiomyogenic differentiation capacity. Therefore, it is suggested that zwitterionic starch based hydrogel is able for the expansion and "stemness " maintenance of BADSCs.


Assuntos
Tecido Adiposo Marrom/citologia , Materiais Biocompatíveis/farmacologia , Diferenciação Celular/efeitos dos fármacos , Hidrogel de Polietilenoglicol-Dimetacrilato/farmacologia , Amido/química , Células-Tronco/citologia , Engenharia Tecidual/métodos , Tecido Adiposo Marrom/efeitos dos fármacos , Animais , Materiais Biocompatíveis/química , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Teste de Materiais , Oligopeptídeos/química , Ratos , Ratos Sprague-Dawley , Células-Tronco/efeitos dos fármacos
8.
Soft Matter ; 13(48): 9237-9245, 2017 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-29199306

RESUMO

The lack of sufficient mechanical properties restricts the application of polysaccharide-based hydrogels in the field of biomedicine, especially load-bearing tissue repair. Nowadays, double network (DN) hydrogels have aroused great interest through special cooperation between two contrasting networks. Inspired by this idea, here, we devised a new strategy to prepare a pectin-Fe3+/polyacrylamide hybrid DN hydrogel using a simple two-step method. The introduction of Fe3+ ions into a pectin network to produce strong reversible ionic complexation, results in excellent toughness. Under optimal conditions, our hybrid DN hydrogels possessed tensile strength as high as 0.9 MPa, corresponding to a high strain of 1300%. Besides, our hybrid DN hydrogels also exhibited superb stiffness (elastic modulus ∼ 1.46 MPa), toughness (fracture energy ∼ 3785 J m-2), and water absorption capacity (85%). Loading-unloading tests showed that the internal fracture process of the hydrogels was continuous. Owing to the reversible structure of Fe3+-pectin complexation, the hybrid DN hydrogels also showed good fatigue resistance, notch-insensitivity and recoverability. This type of polysaccharide-based hydrogel has potential to broaden the application in the load-bearing tissue repair field.

9.
Carbohydr Polym ; 177: 86-96, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-28962799

RESUMO

Multifunctional capsules have great applications in biomedical fields. In this study, novel polysaccharide-based nanocapsules were prepared via a layer-by-layer technique using silica as the templates. The shell was constructed based on the electrostatic interactions between pectin and chitosan. The pectin-chitosan nanocapsules ((Pec/Cs)3Pec) could keep good colloidal stability within 96h in PBS solution and 48h in BSA solution. Meanwhile, the nanocapsules exhibited a high drug loading and pH-sensitive release property for doxorubicin hydrochloride. Moreover, (Pec/Cs)3Pec nanocapsules had no cytotoxicity to both human hepatocellular carcinoma cells (HepG2 cells) and mouse fibroblast cells (L929 cells). More importantly, (Pec/Cs)3Pec nanocapsules could be more easily uptaken by HepG2 cells when compared with L929 cells. In vitro anticancer activity tests indicated the carriers could effectively kill HepG2 cells. Overall, (Pec/Cs)3Pec nanocapsules have great potential as a novel anticancer drug carrier as a result of their pH-sensitivity, good colloidal stability and anticancer activity.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Nanocápsulas/química , Pectinas/química , Animais , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Quitosana/química , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Células Hep G2 , Humanos , Nanocápsulas/toxicidade
10.
ACS Nano ; 11(6): 5474-5488, 2017 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-28590722

RESUMO

Stem cell implantation strategy has exhibited potential to treat the myocardial infarction (MI), however, the low retention and survival limit their applications due to the reactive oxygen species (ROS) microenvironment after MI. In this study, the fullerenol nanoparticles are introduced into alginate hydrogel to create an injectable cell delivery vehicle with antioxidant activity. Results suggest that the prepared hydrogels exhibit excellent injectable and mechanical strength. In addition, the fullerenol/alginate hydrogel can effectively scavenge the superoxide anion and hydroxyl radicals. Based on these results, the biological behaviors of brown adipose-derived stem cells (BADSCs) seeded in fullerenol/alginate hydrogel were investigated in the presence of H2O2. Results suggest that the fullerenol/alginate hydrogels have no cytotoxicity effects on BADSCs. Moreover, they can suppress the oxidative stress damage of BADSCs and improve their survival capacity under ROS microenvironment via activating the ERK and p38 pathways while inhibiting JNK pathway. Further, the addition of fullerenol can improve the cardiomyogenic differentiation of BADSCs even under ROS microenvironment. To assess its therapeutic effects in vivo, the fullerenol/alginate hydrogel loaded with BADSCs were implanted in the MI area in rats. Results suggest that the fullerenol/alginate hydrogel can effectively decrease ROS level in MI zone, improve the retention and survival of implanted BADSCs, and induce angiogenesis, which in turn promote cardiac functional recovery. Therefore, the fullerenol/alginate hydrogel can act as injectable cell delivery vehicles for cardiac repair.

11.
Acta Biomater ; 55: 420-433, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28391053

RESUMO

Peritoneal adhesion is very common after abdominal and pelvic surgery, which leads to a variety of severe complications. Although numerous pharmacological treatments and barrier-based devices have been investigated to minimize or prevent postoperative adhesion, the clinical efficacy is not very encouraging. In this work, a biodegradable and thermoreversible galactose modified xyloglucan (mXG) hydrogel was developed and the efficacy of mXG hydrogel in preventing postoperative peritoneal adhesion was investigated. The 4% (w/v) mXG solution was a free flowing sol at low temperature, but could rapidly convert into a physical hydrogel at body temperature without any extra additives or chemical reactions. In vitro cell tests showed that mXG hydrogel was non-toxic and could effectively resist the adhesion of fibroblasts. Moreover, in vitro and in vivo degradation experiments exhibited that mXG hydrogel was degradable and biocompatible. Finally, the rat model of sidewall defect-cecum abrasion was employed to evaluate the anti-adhesion efficacy of the mXG hydrogel. The results demonstrated that mXG hydrogel could effectively prevent postoperative peritoneal adhesion without side effects. The combination of suitable gel temperature, appropriate biodegradation period, and excellent postoperative anti-adhesion efficacy make mXG hydrogel a promising candidate for the prevention of postsurgical peritoneal adhesion. STATEMENT OF SIGNIFICANCE: Despite numerous drugs or barrier-based devices have been developed to prevent postoperative adhesion, few solutions have proven to be uniformly effective in subsequent clinical trials. In the present study, we developed a biodegradable and thermoreversible galactose modified xyloglucan (mXG) hydrogel by green enzymatic reaction without using any organic reagents. The developed physical mXG hydrogel not only showed excellent injectability, appropriate gelation time and temperature, but also exhibited excellent biocompatibility and biodegradability both in vitro and in vivo. In addition, mXG hydrogel was easy to handle and could effectively prevent postoperative adhesion without side effects in a rat model of sidewall defect-bowel abrasion. Our study provide a safe and effective postoperative anti-adhesion material which may have potential applications in clinical practice.


Assuntos
Implantes Absorvíveis , Glucanos , Hidrogéis , Aderências Teciduais/prevenção & controle , Xilanos , Animais , Linhagem Celular , Glucanos/química , Glucanos/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Camundongos , Ratos Sprague-Dawley , Aderências Teciduais/metabolismo , Aderências Teciduais/patologia , Xilanos/química , Xilanos/farmacologia
12.
J Phys Chem B ; 121(4): 800-814, 2017 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-28060509

RESUMO

Prediction of the diffusion coefficient of solute, especially bioactive molecules, in hydrogel is significant in the biomedical field. Considering the randomness of solute movement in a hydrogel network, a physical diffusion RMP-1 model based on obstruction theory was established in this study. The physical properties of the solute and the polymer chain and their interactions were introduced into this model. Furthermore, models RMP-2 and RMP-3 were established to understand and predict the diffusion behaviors of proteins in hydrogel. In addition, zwitterionic poly(sulfobetaine methacrylate) (PSBMA) hydrogels with wide range and fine adjustable mesh sizes were prepared and used as efficient experimental platforms for model validation. The Flory characteristic ratios, Flory-Huggins parameter, mesh size, and polymer chain radii of PSBMA hydrogels were determined. The diffusion coefficients of the proteins (bovine serum albumin, immunoglobulin G, and lysozyme) in PSBMA hydrogels were studied by the fluorescence recovery after photobleaching technique. The measured diffusion coefficients were compared with the predictions of obstruction models, and it was found that our model presented an excellent predictive ability. Furthermore, the assessment of our model revealed that protein diffusion in PSBMA hydrogel would be affected by the physical properties of the protein and the PSBMA network. It was also confirmed that the diffusion behaviors of protein in zwitterionic hydrogels can be adjusted by changing the cross-linking density of the hydrogel and the ionic strength of the swelling medium. Our model is expected to possess accurate predictive ability for the diffusion coefficient of solute in hydrogel, which will be widely used in the biomedical field.


Assuntos
Difusão , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Imunoglobulina G/química , Metacrilatos/química , Muramidase/química , Soroalbumina Bovina/química , Animais , Bovinos , Modelos Moleculares , Muramidase/metabolismo
13.
ACS Appl Mater Interfaces ; 8(24): 15710-23, 2016 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-27249052

RESUMO

In this work, a novel starch-based zwitterionic copolymer, starch-graft-poly(sulfobetaine methacrylate) (ST-g-PSBMA), was synthesized via Atom Transfer Radical Polymerization. Starch, which formed the main chain, can be degraded completely in vivo, and the pendent segments of PSBMA endowed the copolymer with excellent protein resistance properties. This ST-g-PSBMA copolymer could self-assemble into a physical hydrogel in normal saline, and studies of the formation mechanism indicated that the generation of the physical hydrogel was driven by electrostatic interactions between PSBMA segments. The obtained hydrogels were subjected to detailed analysis by scanning electron microscopy, swelling ratio, protein resistance, and rheology tests. Toxicity and hemolysis analysis demonstrated that the ST-g-PSBMA hydrogels possess excellent biocompatibility and hemocompatibility. Moreover, the cytokine secretion assays (IL-6, TNF-α, and NO) confirmed that ST-g-PSBMA hydrogels had low potential to trigger the activation of macrophages and were suitable for in vivo biomedical applications. On the basis of these in vitro results, the ST-g-PSBMA hydrogels were implanted in SD rats. The tissue responses to hydrogel implantation and the hydrogel degradation in vivo were determined by histological analysis (Hematoxylin and eosin, Van Gieson, and Masson's Trichrome stains). The results presented in this study demonstrate that the physical cross-linking, starch-based zwitterionic hydrogels possess excellent protein resistance, low macrophage-activation properties, and good biocompatibility, and they are a promising candidate for an in vivo biomedical application platform.


Assuntos
Materiais Biocompatíveis/química , Hidrogéis/química , Hidrogéis/farmacologia , Macrófagos/efeitos dos fármacos , Amido/química , Amido/farmacologia , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/normas , Sobrevivência Celular/efeitos dos fármacos , Metacrilatos , Polímeros , Ratos , Ratos Sprague-Dawley , Amido/ultraestrutura
14.
ACS Appl Mater Interfaces ; 8(7): 4385-98, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26835968

RESUMO

Over the last few decades, nanoparticles have been emerging as useful means to improve the therapeutic efficacy of drug delivery and medical diagnoses. However, the heterogeneity and complexity of blood as a medium is a fundamental problem; large amounts of protein can be adsorbed onto the surface of nanoparticles and cause their rapid clearance before reaching their target sites, resulting in the failure of drug delivery. To overcome this challenge, we present a rationally designed starch derivative (SB-ST-OC) with both a superhydrophilic moiety of zwitterionic sulfobetaine (SB) and a hydrophobic segment of octane (OC) as functional groups, which can self-assemble into "stealth" micelles (SSO micelles). The superhydrophilic SB kept the micelles stable against aggregation in complex media and imbued them with "stealth" properties, eventually extending their circulation time in blood. In stability and hemolysis tests the SSO micelles showed excellent protein resistance properties and hemocompatibility. Moreover, a phagocytosis test and cytokine secretion assay confirmed that the SSO micelles had less potential to trigger the activation of macrophages and were more suitable as a drug delivery candidate in vivo. On the basis of these results, doxorubicin (DOX), a hydrophobic drug, was used to investigate the potential application of this novel starch derivative in vivo. The results of the pharmacokinetic study showed that the values of the plasma area under the concentration curve (AUC) and elimination half-life (T1/2) of the SSO micelles were higher than those of micelles without SB modifications. In conclusion, the combination of excellent protein resistance, lower macrophage activation, and longer circulation time in vivo makes this synthesized novel starch derivative a promising candidate as a hydrophobic drug carrier for long-term circulation in vivo.


Assuntos
Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos , Nanopartículas/administração & dosagem , Neoplasias/tratamento farmacológico , Doxorrubicina/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Macrófagos/efeitos dos fármacos , Micelas , Nanopartículas/química , Neoplasias/patologia , Polímeros/administração & dosagem , Polímeros/química , Amido/química
15.
ACS Appl Mater Interfaces ; 8(7): 4442-55, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26817499

RESUMO

Three-dimensional (3D) cell encapsulation in hydrogel provides superb methods to investigate the biochemical cues in directing cellular fate and behaviors outside the organism, the primary step of which is to establish suitable "blank platform" to mimic and simplify native ECM microenvironment. In this study, zwitterionic starch-based "clickable" hydrogels were fabricated via a "copper- and light- free" Michael-type "thiol-ene" addition reaction between acylated-modified sulfobetaine-derived starch (SB-ST-A) and dithiol-functionalized poly(ethylene glycol) (PEG-SH). By incorporating antifouling SB-ST and PEG, the hydrogel system would be excellently protected from nontarget protein adsorption to act as a "blank platform". The hydrogels could rapidly gel under physiological conditions in less than 7 min. Dynamic rheology experiments suggested the stiffness of the hydrogel was close to the native tissues, and the mechanical properties as well as the gelation times and swelling behaviors could be easily tuned by varying the precursor proportions. The protein and cell adhesion assays demonstrated that the hydrogel surface could effectively resist nonspecific protein and cell adhesion. The degradation study in vitro confirmed that the hydrogel was biodegradable. A549 cells encapsulated in the hydrogel maintained high viability (up to 93%) and started to proliferate in number and extend in morphology after 2 days' culture. These results indicated the hydrogel presented here could be a potential candidate as "blank platform" for 3D cell encapsulation and biochemical cues induced cellular behavior investigation in vitro.


Assuntos
Materiais Biocompatíveis/farmacologia , Técnicas de Cultura de Células/métodos , Rastreamento de Células/métodos , Neoplasias/diagnóstico por imagem , Materiais Biocompatíveis/química , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Hidrogéis/química , Hidrogéis/farmacologia , Neoplasias/patologia , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Amido/química
16.
Adv Healthc Mater ; 5(4): 474-88, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26626543

RESUMO

Cardiac tissue engineering is an effective method to treat the myocardial infarction. However, the lack of electrical conductivity of biomaterials limits their applications. In this work, a homogeneous electronically conductive double network (HEDN) hydrogel via one-step facile strategy is developed, consisting of a rigid/hydrophobic/conductive network of chemical crosslinked poly(thiophene-3-acetic acid) (PTAA) and a flexible/hydrophilic/biocompatible network of photo-crosslinking methacrylated aminated gelatin (MAAG). Results suggest that the swelling, mechanical, and conductive properties of HEDN hydrogel can be modulated via adjusting the ratio of PTAA network to MAAG network. HEDN hydrogel has Young's moduli ranging from 22.7 to 493.1 kPa, and its conductivity (≈10(-4) S cm(-1)) falls in the range of reported conductivities for native myocardium tissue. To assess their biological activity, the brown adipose-derived stem cells (BADSCs) are seeded on the surface of HEDN hydrogel with or without electrical stimulation. Our data show that the HEDN hydrogel can support the survival and proliferation of BADSCs, and that it can improve the cardiac differentiation efficiency of BADSCs and upregulate the expression of connexin 43. Moreover, electrical stimulation can further improve this effect. Overall, it is concluded that the HEDN hydrogel may represent an ideal scaffold for cardiac tissue engineering.


Assuntos
Condutividade Elétrica , Hidrogéis/química , Miócitos Cardíacos/citologia , Células-Tronco/citologia , Engenharia Tecidual , Acetatos/química , Tecido Adiposo Marrom/citologia , Animais , Materiais Biocompatíveis/química , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular/efeitos dos fármacos , Conexina 43/genética , Conexina 43/metabolismo , Módulo de Elasticidade , Gelatina/química , Camundongos , Tiofenos/química , Tecidos Suporte/química , Regulação para Cima
17.
Mater Sci Eng C Mater Biol Appl ; 58: 278-85, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26478312

RESUMO

With the aim to explore a membrane system with appropriate degradation rate and excellent cell-occlusiveness for guided tissue regeneration (GTR), a series of poly(D, L-lactic acid) (PDLLA)/poly(D, L-lactic-co-glycolic acid) (PLGA) (100/0, 70/30, 50/50, 30/70, 0/100, w/w) composite membranes were fabricated via electrospinning. The fabricated membranes were evaluated by morphological characterization, water contact angle measurement and tensile test. In vitro degradation was characterized in terms of the weight loss and the morphological change. Moreover, in vitro cytologic research revealed that PDLLA/PLGA composite membranes could efficiently inhibit the infiltration of 293 T cells. Finally, subcutaneous implant test on SD rat in vivo showed that PDLLA/PLGA (70/30, 50/50) composite membranes could function well as a physical barrier to prevent cellular infiltration within 13 weeks. These results suggested that electrospun PDLLA/PLGA (50/50) composite membranes could serve as a promising barrier membrane for guided tissue regeneration due to suitable biodegradability, preferable mechanical properties and excellent cellular shielding effects.


Assuntos
Materiais Biocompatíveis/química , Ácido Láctico/química , Ácido Poliglicólico/química , Animais , Materiais Biocompatíveis/farmacologia , Adesão Celular/efeitos dos fármacos , Regeneração Tecidual Guiada , Células HEK293 , Humanos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Ratos , Ratos Sprague-Dawley , Resistência à Tração , Água/química
18.
Mater Sci Eng C Mater Biol Appl ; 50: 201-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25746263

RESUMO

Gelatin contains many functional motifs which can modulate cell specific adhesion, so we modified polycarbonate urethane (PCU) scaffold surface by immobilization of gelatin. PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatins onto the surface of aminated PCU scaffolds. To increase the immobilization amount of gelatin, poly(ethylene glycol) methacrylate (PEGMA) was grafted onto PCU scaffolds by surface initiated atom transfer radical polymerization. Then, following amination and immobilization, PCU-g-PEGMA-g-gelatin scaffolds were obtained. Both modified scaffolds were characterized by chemical and biological methods. After immobilization of gelatin, the microfiber surface became rough, but the original morphology of scaffolds was maintained successfully. PCU-g-PEGMA-g-gelatin scaffolds were more hydrophilic than PCU-g-gelatin scaffolds. Because hydrophilic PEGMA and gelatin were grafted and immobilized onto the surface, the PCU-g-PEGMA-g-gelatin scaffolds showed low platelet adhesion, perfect anti-hemolytic activity and excellent cell growth and proliferation capacity. It could be envisioned that PCU-g-PEGMA-g-gelatin scaffolds might have potential applications in tissue engineering artificial scaffolds.


Assuntos
Gelatina/farmacologia , Células Endoteliais da Veia Umbilical Humana/citologia , Interações Hidrofóbicas e Hidrofílicas , Proteínas Imobilizadas/farmacologia , Metacrilatos/farmacologia , Polietilenoglicóis/farmacologia , Poliuretanos/farmacologia , Tecidos Suporte/química , Animais , Adesão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Microscopia Eletrônica de Varredura , Espectroscopia Fotoeletrônica , Adesividade Plaquetária/efeitos dos fármacos , Coelhos , Espectroscopia de Infravermelho com Transformada de Fourier , Água
19.
ACS Appl Mater Interfaces ; 7(12): 6505-17, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25756853

RESUMO

Myocardial infarction (MI) still represents the "Number One Killer" in the world. The lack of functional vasculature of the infracted myocardium under hypoxia is one of the main problems for cardiac repair. In this study, a thermosensitive chitosan chloride-RoY (CSCl-RoY) hydrogel was developed to improve angiogenesis under hypoxia after MI. First, RoY peptides were conjugated onto the CSCl chain via amide linkages, and our data show that the conjugation of RoY peptide to CSCl does not interfere with the temperature sensitivity. Then, the effect of CSCl-RoY hydrogels on vascularization in vitro under hypoxia was investigated using human umbilical vein endothelial cells (HUVECs). Results show that CSCl-RoY hydrogels can promote the survival, proliferation, migration and tube formation of HUVECs under hypoxia compared with CSCl hydrogel. Further investigations suggest that CSCl-RoY hydrogels can modulate the expression of membrane surface GRP78 receptor of HUVECs under hypoxia and then activate Akt and ERK1/2 signaling pathways related to cell survival/proliferation, thereby enhancing angiogenic activity of HUVECs under hypoxia. To assess its therapeutic properties in vivo, a MI model was induced in rats by the left anterior descending artery ligation. CSCl or CSCl-RoY hydrogels were injected into the border of infracted hearts. The results demonstrate that the introduction of RoY peptide can not only improve angiogenesis at MI region but also improve the cardiac functions. Overall, we conclude that the CSCl-RoY may represent an ideal scaffold material for injectable cardiac tissue engineering.


Assuntos
Quitosana/química , Coração/fisiopatologia , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Hipóxia/fisiopatologia , Neovascularização Fisiológica , Peptídeos/química , Engenharia Tecidual/instrumentação , Tecidos Suporte/química , Animais , Proliferação de Células , Sobrevivência Celular , Quitosana/administração & dosagem , Coração/crescimento & desenvolvimento , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/administração & dosagem , Hipóxia/tratamento farmacológico , Hipóxia/genética , Hipóxia/metabolismo , Masculino , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/fisiopatologia , Peptídeos/administração & dosagem , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
20.
Mater Sci Eng C Mater Biol Appl ; 48: 220-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25579917

RESUMO

The action mode of quaternized carboxymethyl chitosan/poly(amidoamine) dendrimer core-shell nanoparticles (CM-HTCC/PAMAM) against Escherichia coli (E. coli) was investigated via a combination of approaches including measurements of cell membrane integrity, outer membrane (OM) and inner membrane (IM) permeability, and scanning electron microscopy (SEM). CM-HTCC/PAMAM dendrimer nanoparticles likely acted in a sequent event-driven mechanism, beginning with the binding of positively charged groups from nanoparticle surface with negative cell surface, thereby causing the disorganization of cell membrane, and subsequent leakage of intracellular components which might ultimately lead to cell death. Moreover, the chain conformation of polymers was taken into account for a better understanding of the antibacterial action mode by means of viscosity and GPC measurements. High utilization ratio of positive charge and large specific surface area generated from a compacted conformation of CM-HTCC/PAMAM, significantly different from the extended conformation of HTCC, were proposed to be involved in the antibacterial action.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Dendrímeros/química , Escherichia coli/efeitos dos fármacos , Nanopartículas/química , Permeabilidade da Membrana Celular/efeitos dos fármacos , Quitosana/análogos & derivados , Quitosana/química , Dendrímeros/farmacologia , Membranas Intracelulares/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Permeabilidade , Eletricidade Estática , Viscosidade
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