Degradable natural polymer hydrogels for articular cartilage tissue engineering

Articular cartilage has poor ability to heal once damaged. Tissue engineering with scaffolds of polymer hydrogels is promising for cartilage regeneration and repair. Polymer hydrogels composed of highly hydrated crosslinked networks mimic the collagen networks of the cartilage extracellular matrix and thus are employed as inserts at cartilage defects not only to temporarily relieve the pain but also to support chondrocyte proliferation and neocartilage regeneration. The biocompatibility, biofunctionality, mechanical properties, and degradation of the polymer hydrogels are the most important parameters for hydrogel‐based cartilage tissue engineering. Degradable biopolymers with natural origin have been widely used as biomaterials for tissue engineering because of their outstanding biocompatibility, low immunological response, low cytotoxicity, and excellent capability to promote cell adhesion, proliferation, and regeneration of new tissues. This review covers several important natural proteins (collagen, gelatin, fibroin, and fibrin) and polysaccharides (chitosan, hyaluronan, alginate and agarose) widely used as hydrogels for articular cartilage tissue engineering. The mechanical properties, structures, modification, and structure–performance relationship of these hydrogels are discussed since the chemical structures and physical properties dictate the in vivo performance and applications of polymer hydrogels for articular cartilage regeneration and repair. © 2012 Society of Chemical Industry     

Development of a novel glucosamine/silk fibroin–chitosan blend porous scaffold for cartilage tissue engineering applications

Silk fibroin–chitosan blend is reported to be an attractive scaffold material for tissue engineering applications. In our earlier study, we developed a scaffold having an optimal silk fibroin–chitosan blend ratio of 80:20 and proved its potentiality for cartilage tissue engineering applications. Glucosamine is one of the major structural components of cartilage tissue. The present work investigates the effect of glucosamine components on the physicochemical and biocompatibility properties of this scaffold. To this end, varied amounts of glucosamine were added to silk fibroin–chitosan blend with the aim of improving various scaffold properties. The addition of glucosamine components did not show any significant change in physicochemical properties of silk fibroin–chitosan blend scaffolds. The composite scaffold showed an open pore structure with desired pore size and porosity. However, cell culture study using human mesenchymal stem cells derived from umbilical cord blood revealed an overall increase in cell supportive properties of glucosamine-added scaffolds. Cell viability, cell proliferation and glycosaminoglycan assays confirmed enhanced cell viability and proliferation of mesenchymal stem cells. Thus, this study demonstrated the beneficial effect of glucosamine on improving the cell supportive property of silk fibroin–chitosan blend scaffolds making it more potential for cartilage tissue regeneration. To the best of our knowledge, this is the first report on the study of glucosamine-added silk fibroin–chitosan blend porous scaffolds seeded with mesenchymal stem cells derived from umbilical cord blood.     

Bioactive monetite‐containing whisker‐like fibers reinforced chitosan scaffolds

The aim of this work was to develop bioactive chitosan scaffolds reinforced with monetite‐containing whisker‐like fibers. The fibers synthesized by homogeneous precipitation were characterized as monetite/hydroxyapatite short fibers (MAFs), using XRD, FTIR and SEM. The pure chitosan and MAFs/chitosan composite scaffolds were produced by freeze‐drying, and characterized with respect to porosity, pore size, swelling behavior, compressive strength and modulus, and in vitro bioactivity. The incorporation of MAFs in chitosan matrices led to increase the pore size, according to the evaluation by FE‐SEM, and decrease the porosity of composite scaffolds. The swelling ratio decreased as MAFs content of scaffolds increased. The compressive strength and modulus of scaffolds were improved by an increase in MAFs content. The noncross‐linked scaffolds with a chitosan: MAFs weight ratio of 1:1 (CW3) showed a porosity of 75.5%, and the strength and modulus of 259 kPa and 2.8 MPa in dry state, respectively. The crosslinking by glutaraldehyde resulted in improved mechanical properties. The strength and modulus of cross‐linked CW3 scaffolds in wet state reached to 345 kPa and 1.8 MPa, respectively. The in vitro bioactivity of the reinforced scaffolds, evaluated by FE‐SEM/EDS, XRD, and ATR‐FTIR, was confirmed by the formation of a carbonated apatite layer on their surfaces when they soaked in simulated body fluid (SBF). The results of this initial study indicate that the monetite‐containing whisker‐like fibers may be an appropriate reinforcement of chitosan scaffolds.     

Characterization of the morphology and hydrophilicity of chitosan/caffeic acid hybrid scaffolds

The morphology and affinity of a scaffold influence the attachment of cells to its surfaces. In this study, the morphology and hydrophilicity of chitosan/caffeic acid hybrid scaffolds were investigated. Grafting caffeic acid onto chitosan hybrid scaffolds by using high levels of potassium persulfate produced scaffolds with looser morphology and higher porosity, as indicated by scanning electron microscopy (SEM) and porosity analysis. SEM analysis showed that the prepared scaffolds had a macroporous morphology with interconnected pores. Differential scanning calorimetry (DSC) revealed that the scaffolds’ hydrophilicity decreased after caffeic acid grafting. The scaffolds were cultured with human osteosarcoma UMR-106 cells, but SEM analysis showed that cell attachment was poor. However, calcification of the scaffolds promoted the attachment of UMR-106 cells onto the scaffold. This study shows that calcified chitosan/caffeic acid hybrid scaffolds could be suitable for use in hard-tissue engineering.     

Preparation and cell compatibility evaluation of chitosan/collagen composite scaffolds using amino acids as crosslinking bridges

In this study, a novel freeze‐gelation method instead of the conventional freeze‐drying method was used to fabricate porous chitosan/collagen‐based composite scaffolds for skin‐related tissue engineering applications. To improve the performance of chitosan/collagen composite scaffolds, we added 1‐ethyl‐3‐(3‐dimethylaminopropyl)‐carbodiimide (EDC) and amino acids (including alanine, glycine, and glutamic acid) in the fabrication procedure of the composite scaffolds, in which amino acid molecules act as crosslinking bridges to enhance the EDC‐mediated crosslinking. This novel combination enhanced the tensile strength of the scaffolds from 0.70 N/g for uncrosslinked scaffolds to 2.2 N/g for crosslinked ones; the crosslinked scaffolds also exhibited slower degradation rates. The hydrophilicity of the scaffolds was also significantly enhanced by the addition of amino acids to the scaffolds. Cell compatibility was demonstrated by the in vitro culture of human skin fibroblasts on the scaffolds. The fibroblasts attached and proliferated well on the chitosan/collagen composite scaffolds, especially the one with glutamic acid molecules as crosslinking bridges, whereas cells did not grow on the chitosan scaffolds. Our results suggest that the collagen‐modified chitosan scaffolds with glutamic acid molecules as crosslinking bridges are very promising biomaterials for skin‐related tissue engineering applications because of their enhanced tensile strength and improved cell compatibility with skin fibroblasts. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Chitosan/gelatin porous bone scaffolds made by crosslinking treatment and freeze‐drying technology: Effects of crosslinking durations on the porous structure,compressive strength,and in vitro cytotoxicity

In this study, freezing was used to separate a solute (polymer) and solvent (deionized water). The polymer in the ice crystals was then crosslinked with solvents, and this diminished the linear pores to form a porous structure. Gelatin and chitosan were blended and frozen, after which crosslinking agents were added, and the whole was frozen again and then freeze‐dried to form chitosan/gelatin porous bone scaffolds. Stereomicroscopy, scanning electron microscopy, compressive strength testing, porosity testing, in vitro biocompatibility, and cytotoxicity were used to evaluate the properties of the bone scaffolds. The test results show that both crosslinking agents, glutaraldehyde (GA) and 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide, were able to form a porous structure. In addition, the compressive strength increased as a result of the increased crosslinking time. However, the porosity and cell viability were not correlated with the crosslinking times. The optimal porous and interconnected pore structure occurred when the bone scaffolds were crosslinked with GA for 20 min. It was proven that crosslinking the frozen polymers successfully resulted in a division of the linear pores, and this resulted in interconnected multiple pores and a compressively strong structure. The 48‐h cytotoxicity did not affect the cell viability. This study successfully produced chitosan/gelatin porous materials for biomaterials application. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41851.     

Development of fibrin conjugated chitosan/nano β‐TCP composite scaffolds with improved cell supportive property for bone tissue regeneration

In the present study, an attempt has been made to improve cell supportive property of chitosan/nano beta tri‐calcium phosphate (β‐TCP) composite scaffolds by modification of scaffold surface with fibrin using ethyl‐3‐(3‐dimethylaminopropyl) carbodimide (EDC) as crosslinking agent. The developed fibrin conjugated chitosan/nano β‐TCP composite scaffolds possess desired pore size and porosity in the range of 45–151 µm and 81.4 ± 4.1%, respectively. No significant change in compressive strength of scaffolds was observed before and after fibrin conjugation. The calculated compressive strength of fibrin conjugated and non‐conjugated chitosan/nano β‐TCP scaffolds are 2.71 ± 0.14 MPa and 2.67 ± 0.11 MPa, respectively. Results of cell culture study have further shown an enhanced cell attachment, cell number, proliferation, differentiation, and mineralization on fibrin conjugated chitosan/nano β‐TCP scaffold. The uniform cell distribution over the scaffold surface and cell infiltration into the scaffold pores were assessed by confocal laser scanning microscopy. Furthermore, higher expression of osteogenic specific genes such as bone sialo protein, osteonectin, alkaline phosphatase, and osteocalcin (OC) on fibrin conjugated scaffolds was observed when compared to scaffolds without fibrin. Altogether, results indicate the potentiality of developed fibrin conjugated composite scaffolds for bone tissue engineering applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41534.     

Bone Regeneration in rat using a gelatin/bioactive glass nanocomposite scaffold along with endothelial cells (HUVECs)

In our previous study, a three‐dimensional gelatin/bioactive glass nanocomposite scaffold with a total porosity of about 85% and pore sizes ranging from 200 to 500 μm was prepared through layer solvent casting combined with lamination technique. The aim of this study was to evaluate in vitro biocompatibility and in vivo bone regeneration potential of these scaffolds with and without endothelial cells when implanted into a critical‐sized rat calvarial defect. MTT assay, SEM observation, and DAPI staining were used to evaluate cell viability and adhesion in macroporous scaffolds and results demonstrated that the scaffolds were biocompatible enough to support cell attachment and proliferation. To investigate the in vivo osteogenesis of the scaffold, blank scaffolds and endothelial/scaffold constructs were implanted in critical‐sized defects, whereas in control group defects were left untreated. Bone regeneration and vascularization were evaluated at 1, 4, and 12 weeks postsurgery by histological, immunohistochemical, and histomorphometric analysis. It was shown that both groups facilitated bone growth into the defect area but improved bone regeneration was seen with the incorporation of endothelial cells. The data showed that the porous Gel/BaG nanocomposite scaffolds could well support new bone formation, indicating that the proposed strategy is a promising alternative for tissue‐engineered bone defects.     

Air‐dried 3D‐collagen–chitosan biocomposite scaffold for tissue engineering application

Collagen–chitosan scaffolds of different compositions were developed using emulsion air‐drying method. The scaffolds prepared adding 10–30 wt% of chitosan to collagen improved the mechanical properties of the composite scaffold, and 7:3 ratio (collagen :chitosan) was found to be a better composite having a tensile strength of 13.57 MPa with 9% elongation at break. The water‐uptake characteristics were performed at different pH and found to be ameliorated for the composite scaffolds compared to pure collagen and chitosan scaffold, respectively. The pores ranging from 100 to 300 μm were well interconnected, and their distribution was fairly homogeneous in the scaffold as observed through scanning electron microscopy. Furthermore, the scaffold decreased the bacterial counts and supported fibroblasts attachment and proliferation, thus demonstrating this composite to be a good substrate for biomedical application.POLYM. COMPOS., 33:2029–2035, 2012. © 2012 Society of Plastics Engineers     

Fabrication and characterization of natural origin chitosan‐ gelatin‐alginate composite scaffold by foaming method without using surfactant

A natural origin tripolymer scaffold from chitosan, gelatin, and alginate was fabricated by applying foaming method without adding any foam stabilizing surfactant. Previously, in foaming method of scaffold fabrication, toxic surfactants were used to stabilize the foam, but in this work, the use of surfactant has been avoided strictly, which can provide better environment for cellular response and viability. In foaming method, stable foam is produced simply by agitating the polymer (alginate‐gelatin) solution, and the foam is crosslinked with CaCl₂, glutaraldehyde, and chitosan to produce tripolymer alginate‐gelatin‐chitosan composite scaffold. Microscopic images of the composite scaffold revealed the presence of interconnected pores, mostly spread over the entire surface of the scaffold. The scaffold has a porosity of 90% with a mean pore size of 57 μm. Swelling and degradation studies of the scaffold showed that the scaffold possesses excellent properties of hydrophilicity and biodegradability. In vitro cell culture studies by seeding L929 mouse fibroblast cells on scaffold revealed excellent cell viability, proliferation rate and adhesion as indicated by MTT assay, DNA quantification, and phase contrast microscopy of cell‐scaffold construct. The natural origin composite scaffold fabricated by the simplest method i.e., foaming method, but without adding any surfactant, is cheap, biocompatible, and it might find potential applications in the field of tissue engineering. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Evaluation of poly(L-lactide) and chitosan composite scaffolds for cartilage tissue regeneration

The present study delineates the development of chitosan and poly(L-lactide) (PLLA) scaffolds cross-linked using a mixture of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC), n-hydroxysuccinimide (NHS), and chondroitin sulfate (CS) for cartilage tissue engineering applications. Chitosan and PLLA were varied in concentration for developing scaffolds and prepared by freeze-drying method. The various scaffolds were studied using scanning electron microscopy (SEM), porosity by mercury intrusion porosimeter, and the molecular interactions among polymers using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) studies. Differential scanning calorimetry was used to predict the thermal properties of the scaffolds. The mechanical properties of the scaffolds were studied using static mechanical tester. The ability of the scaffolds to support chondrocyte proliferation was also studied. The microscopy suggests that the pore size of the scaffolds varied with the composition in the range of 38–172 μm and the porosities in the range of 73–93%. The XRD and the FTIR studies suggested that an alternation in the composition of the scaffolds altered the molecular interactions among the scaffold components. An increase in the chitosan content enhanced the swelling property. The degradation of the scaffolds was least when the proportion of chitosan and PLLA was in the ratio of 70:30. The in vitro cell proliferation study suggested that the developed scaffolds were able to support chondrogenesis, the glycosaminoglycan (GAG) content of the mature chondrocyte was 40 μg/ml and the viability was approximately 90%. Hence, the so designed scaffolds may be tried for cartilage tissue engineering applications.     

聚乙烯醇/牛I型胶原支架材料的制备及评价

研究了一种聚乙烯醇(PVA)和胶原(COL)复合支架材料的制备方法。采用氨基硅烷对PVA海绵表面进行了氨基化修饰后,通过戊二醛溶液交联牛Ⅰ型胶原(COL),最后通过赖氨酸溶液封闭,获得一种PVA/COL复合支架材料。采用扫描电镜(SEM)、X光电子能谱仪(XPS)、傅里叶红外光谱(FT-IR)等手段对支架材料的理化性能进行表征,并通过细胞实验对支架材料的生物学性能进行评价。结果表明,经过COL修饰的PVA孔隙率为21.33%,平均孔径为168.68 ?m且均匀分布,支架材料接触角为20.03°。对支架材料的生物学评价结果表明C3A细胞在复合材料上黏附良好,优于PVA组;CCK-8增殖检测结果表明细胞在复合材料上呈增殖生长趋势,与对照组PVA相比差异显著(P?0.01)。将PVA和COL复合制备得到的支架材料具有良好的理化及生物学特性,具有广阔的应用前景。     

Preparation and characterization of collagen‐based composite conduit for peripheral nerve regeneration

Collagen‐based composite nerve conduit scaffold was prepared by freeze‐drying steam‐extrusion method and modified chemically with glutaraldehyde (GTA) by adding chitosan into collagen. Fourier transform infrared spectroscopy showed that the collagen and chitosan are certainly crosslinked through GTA. It was observed under scanning electron microscope that the modified nerve conduit material is a porous three‐dimensional crosslinked structure and the quantity ratio of the collagen to chitosan has influence on the morphology. The cell proliferation experiment results showed that the collagen‐based composite scaffold prompts the adhesion and proliferation of cells, but as the chitosan increasing, the cell proliferation decreased slightly. The swelling property, the collagenase degradation, and the mechanical property of the scaffold are tested at the quantity ratios of collagen to chitosan 4 : 3, 3 : 1, and 4 : 1 and crosslinking time 0.5 and 1.0 h. The experiments show that the stability of the scaffold is enhanced with decreasing the quantity ratio of collagen to chitosan and increasing crosslinking time. Through the experimental investigations, the modifying technique parameters are discussed and the scaffold exhibits better physical and chemical properties at the quantity ratio of collagen to chitosan 3 : 1 and crosslinking time 0.5 h. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and characterization of collagen/silica composite scaffolds for peripheral nerve regeneration

To improve the regeneration of peripheral nerve system, the silica nanoparticles of various concentrations were synthesized in collagen solution and formed to silica incorporated porous collagen structures. We examined various properties such as morphology, chemical composition, wettability, porosity, swelling ratio and degradation behavior of the composite scaffolds. Schwann cells culture was used to evaluate the effect of the collagen/silica composite materials on nerve regeneration. And the content of DNA in Schwann cells was measured. We ascertained that the silica nanoparticles could be incorporated into collagen scaffolds successfully. The incorporation of silica nanoparticles could increase the hydrophobicity, decrease porosity, swelling ratio and degradation rate of the collagen scaffolds. Further, the attachment and proliferation of Schwann cells on the silica incorporated porous collagen patch was much better than that of the collagen patch as control. The number and DNA contents of the cells on the composite scaffolds increased firstly and then decreased with the increment of nanoparticles concentration. It was optimal to combine silica of 25 μg/mL for achieving best cell attachment and proliferation with the highest DNA contents compared with other samples. These results indicate that silica incorporated porous collagen patch may be potentially used as implanted scaffold materials for the peripheral nerve regeneration.     

Preparation of elastic chitosan/poly(<Emphasis Type="SmallCaps">l</Emphasis>-lactide-co-ε-caprolactone) macroporous scaffolds by acetylation and particulate leaching

For soft tissue engineering applications, 3-D macroporous acetylated chitosan/poly(l-lactideco-ε-caprolactone) (PLCL) scaffolds were prepared by acetylation and particulate leaching using sodium acetate in an acidic water/dioxane solution. Acetylated 5 wt% chitosan/PLCL scaffold of 90% porosity was determined and confirmed through various tests. The physiochemical properties of acetylated chitosan/PLCL hybrid scaffolds were examined by measuring water contact angles, pore morphology and interconnectivity using scanning electron microscopy (SEM), and dye release testing. In addition, mechanical properties such as tensile strength and bending stress recovery for determining the elasticity of scaffolds were measured. The fibroblast cell line NIH-3T3 was used to test relative cell affinities for the acetylated chitosan/PLCL vs. normal chitosan/PLCL films and porous scaffolds. The acetylated chitosan/PLCL films and scaffolds showed a high initial cell adhesion after 4 h of cell culture and increased cell proliferation compared to that of the control. The acetylated chitosan/PLCL scaffolds produced by particulate leaching showed a highly porous structure and improved the biocompatibility and stability of chitosan compared to that of chitosan-coated PLCL scaffolds. Thus, these scaffolds may be very useful for a variety of tissue engineering applications.     

Three-dimensional fibroin/collagen scaffolds derived from aqueous solution and the use for HepG2 culture

Although three-dimensional fibroin scaffolds have been prepared with freeze–drying method, these scaffolds still cannot meet the requirements of tissue engineering. In this article, a new process is described to form fibroin-based porous scaffolds with controllable structure and morphological features. When collagen was added to fibroin solution, the viscosity of the blend solution increased because of the interaction between fibroin and collagen, and then it restrained the unwanted fibroin leaf formation in freezing process that generally appeared in the previous fibroin scaffold preparation. With methanol treatment, the fibroin/collagen scaffolds became water-stable, following the transition from random and -helix to β-sheet conformation. The aqueous-fibroin porous scaffolds had highly homogeneous and interconnected pores with pore sizes ranging from 127 to 833 μm, depending on the fibroin concentration. The porosity of scaffolds was >90%, and the yield strength and modulus were up to 354±25 kPa and 30±0.1 MPa, respectively, when the blend solution, containing 20% collagen, maintained 4% fibroin concentration. Adhesion, spreading and proliferation of HepG2 cells on fibroin and fibroin/collagen blend scaffolds were also observed to investigate the biocompatibility. Scanning electron microscopy (SEM) and MTT analyses demonstrated that the adding of collagen evidently facilitated HepG2 attachment and proliferation in vitro. These new fibroin based three-dimensional scaffolds provided much more excellent properties due to the greatly improved control of pore size, the uniform pore distribution, the hydrophility, the mechanical properties and the biocompatibility compared with those of reported three-dimensional fibroin scaffolds.     

Study of Different Delivery Modes of Chondroitin Sulfate Using Microspheres and Cryogel Scaffold for Application in Cartilage Tissue Engineering

This study focuses on the development of an efficient delivery modes designed for chondroitin sulfate (CS) for application in cartilage tissue engineering. Novel three-dimensional (3-D) scaffold fabricated from natural polymers such as chitosan and gelatin blended with chondroitin sulfate (CGC) were synthesized using cryogelation technology. Other methods to deliver CS were also tried, which included incorporation into microparticles for sustained release and embedding the CS loaded microparticles in CG (chitosan-gelatin) cryogel scaffold. Novel CGC scaffolds were characterized by rheology, scanning electron microscopy (SEM), and mechanical assay. Scaffolds exhibited compression modulus of 50 KPa confirming the utility of these scaffolds for cartilage tissue engineering. Primary goat chondrocytes were used for the in vitro testing of all the delivery modes. So this study shows that CS microparticles when given freely with matrix (chitosan–gelatin) or embedded into scaffold has potential to enhance chondrocyte proliferation together with improved matrix production than in control without microspheres.     

3D打印骨组织支架孔隙结构对支架性能影响的研究进展

从骨组织工程支架孔隙形状、孔径大小、孔隙率、表面粗糙度、连接通路5方面对支架孔的微观结构的研究现状进行了综述。发现梯度结构的支架孔隙形状更接近天然骨,粗糙的表面可以改善细胞的黏附和增殖,非正交连接通路的内部结构可以为后期骨再生提供一个动态的生长空间。     

Composite scaffolds for cartilage tissue engineering based on natural polymers of bacterial origin,thermoplastic poly(3‐hydroxybutyrate) and micro‐fibrillated bacterial cellulose

Cartilage tissue engineering is an emerging therapeutic strategy that aims to regenerate damaged cartilage caused by disease, trauma, ageing or developmental disorder. Since cartilage lacks regenerative capabilities, it is essential to develop approaches that deliver the appropriate cells, biomaterials and signalling factors to the defect site. Materials and fabrication technologies are therefore critically important for cartilage tissue engineering in designing temporary, artificial extracellular matrices (scaffolds), which support 3D cartilage formation. Hence, this work aimed to investigate the use of poly(3‐hydroxybutyrate)/microfibrillated bacterial cellulose (P(3HB)/MFC) composites as 3D‐scaffolds for potential application in cartilage tissue engineering. The compression moulding/particulate leaching technique employed in the study resulted in good dispersion and a strong adhesion between the MFC and the P(3HB) matrix. Furthermore, the composite scaffold produced displayed better mechanical properties than the neat P(3HB) scaffold. On addition of 10, 20, 30 and 40 wt% MFC to the P(3HB) matrix, the compressive modulus was found to have increased by 35%, 37%, 64% and 124%, while the compression yield strength increased by 95%, 97%, 98% and 102% respectively with respect to neat P(3HB). Both cell attachment and proliferation were found to be optimal on the polymer‐based 3D composite scaffolds produced, indicating a non‐toxic and highly compatible surface for the adhesion and proliferation of mouse chondrogenic ATDC5 cells. The large pores sizes (60 ‐ 83 µm) in the 3D scaffold allowed infiltration and migration of ATDC5 cells deep into the porous network of the scaffold material. Overall this work confirmed the potential of P(3HB)/MFC composites as novel materials in cartilage tissue engineering. © 2016 Society of Chemical Industry     

Preparation and characterization of a Bacterial cellulose/Chitosan composite for potential biomedical application

Bacterial cellulose (BC)/Chitosan (Ch) composite has been successfully prepared by immersing wet BC pellicle in Ch solution followed by freeze-drying process. The morphology of BC/Ch composite was examined by scanning electron microscope (SEM) and compared with pristine BC. SEM images show that Ch molecules can penetrate into BC forming three-dimensional multilayered scaffold. The scaffold has very well interconnected porous network structure and large aspect surface. The composite was also characterized by Fourier transform infrared spectrum, X-ray diffraction, thermogravimetric analysis and tensile test. By incorporation of Ch into BC, crystallinity tends to decrease from 82% to 61%, and the thermal stability increases from 263 °C to 296 °C. At the same time, the mechanical properties of BC/Ch composite are maintained at certain levels between BC and Ch. The biocompatibility of composite was preliminarily evaluated by cell adhesion studies. The cells incubated with BC/Ch scaffolds for 48 h were capable of forming cell adhesion and proliferation. It showed much better biocompatibility than pure BC. Since the prepared BC/Ch scaffolds are bioactive and suitable for cell adhesion, these scaffolds can be used for wound dressing or tissue-engineering scaffolds.