Chitosan Gelatin Research Articles

Recapitulating tumour microenvironment in chitosan–gelatin three-dimensional scaffolds: an improvedin vitrotumour model

Owing to the reduced co-relationship between conventional flat Petri dish culture (two-dimensional) and the tumour microenvironment, there has been a shift towards three-dimensional culture systems that show an improved analogy to the same. In this work, an extracellular matrix (ECM)-mimicking three-dimensional scaffold based on chitosan and gelatin was fabricated and explored for its potential as a tumour model for lung cancer. It was demonstrated that the chitosan-gelatin (CG) scaffolds supported the formation of tumoroids that were similar to tumours grown in vivo for factors involved in tumour-cell-ECM interaction, invasion and metastasis, and response to anti-cancer drugs. On the other hand, the two-dimensional Petri dish surfaces did not demonstrate gene-expression profiles similar to tumours grown in vivo. Further, the three-dimensional CG scaffolds supported the formation of tumoroids, using other types of cancer cells such as breast, cervix and bone, indicating a possible wider potential for in vitro tumoroid generation. Overall, the results demonstrated that CG scaffolds can be an improved in vitro tool to study cancer progression and drug screening for solid tumours.

In vitro evaluation of hydroxyapatite–chitosan–gelatin composite membrane in guided tissue regeneration

Resorbable biomaterials have been investigated as barrier membranes to compartmentalize the periodontal defects while selectively guiding osteoprogenitor cell proliferation and bone tissue expansion. Hydroxyapatite (H), chitosan (C), and gelatin (G) have chemical similarity to the structural components of natural bone and their composites have been tested as bone scaffolds. Human mesenchymal stem or stromal cells (hMSCs) are inducible osteoprogenitors and are responsible for bone tissue repair and regeneration. In this study, the dynamic interactions of hMSC with composite hydroxyapatite-chitosan-gelatin (HCG) membranes were investigated. The association of HCG formed a biodegradable membrane with ~60 wt % water and an initial stiffness of ~20 kPa. Preconditioning in serum-containing media resulted in the formation nanopores in the HCG membranes and the increase of extracellular matrix (ECM) protein adsorption. Expression of integrin α(2)β(1) and α(5)β(1) coincided with ECM enrichment, suggesting the enhanced cell-ECM interactions. The elevated expression of bone marker proteins and genes in the HCG membranes suggests the progression of hMSC osteogenic differentiation in the absence of chemical induction. The results showed that the HCG membranes possess sufficient mechanical and structural properties to function as a barrier membrane, and that the adsorbed ECM proteins effectively functionalized the HCG membranes and promoted hMSC osteogenic differentiation.

The fabrication of nanocomposites via calcium phosphate formation on gelatin–chitosan network and the gelatin influence on the properties of biphasic composites

A novel biodegradable polymer–ceramic nanocomposite which consisted of gelatin (Gel), chitosan (CS), and calcium phosphate (CaP) nanoparticles was prepared based on in situ preparation method. The fabricated biocomposites were characterized by FTIR, X-ray diffraction (XRD), transmission electron microscopy (TEM) as well as scanning electron microscope with X-ray elemental analysis (SEM-EDX). The characterization results confirmed that the crystalline calcium phosphate nanoparticles were mineralized in polymeric matrix and the interaction between Ca2+ in calcium phosphate and functional groups in polymers molecular chains was formed. XRD result showed that in addition to hydroxyapatite (HA), Brushite (BR) and tricalcium phosphate (β-TCP) particles also were formed due to lack of complete penetration of the basic solution into the polymeric matrix. However, SEM image indicated that the polymeric matrix has the controlling role in the particle size of calcium phosphate. The size of particles in three component composites was about 100nm while in two component composites proved to be more in μm size. TEM observation supported SEM results and showed that the three component composites have calcium phosphate nanoparticles. The elastic modulus and compressive strength of the composites were also improved by the employment of gelatin and chitosan together, which can make them more beneficial for surgical applications.

Comparison of the properties of multi-composite fish gelatin films with that of mammalian gelatin films

Four types of films viz. gelatin, gelatin–MMT, gelatin–chitosan and gelatin–MMT–chitosan prepared from redsnapper and grouper bone gelatin were compared with the mammalian gelatin films, for their mechanical and barrier properties. Grouper gelatin films had higher tensile strength (TS) and Young’s modulus (YM), but lower elongation at break (EAB) than redsnapper films. Incorporation of MMT and chitosan improved the TS (p<0.05) of the films. Water solubilities were lower (p<0.05) in films incorporated with chitosan compared to simple gelatin film. Protein solubilities were lower in gelatin–MMT films, irrespective of the type of solvent used. The water vapour transmission rates (WVTR) of fish and mammalian gelatin films were similar, but addition of MMT had reduced WVTR (p<0.05). SEM micrographs depicted smoother surface for gelatin–MMT and gelatin–MMT–chitosan films. Thus, composite fish gelatin films made with MMT and chitosan could be the good natural biodegradable films due to their better mechanical and barrier properties.

Preparation, characterization, and induction of cell apoptosis of cocoa procyanidins–gelatin–chitosan nanoparticles

Cocoa procyanidins (CPs)–gelatin–chitosan nanoparticles were fabricated based on the procyanidin–protein and electrostatic interactions, with an objective to enhance the stability and bioactivity of CPs. The CPs were purified using chromatographic methods and analyzed using HPLC equipped with a fluorescence detector (FLD) and mass spectrometer (MS). The purified CPs had a purity of 53.1% (w/w) and contained procyanidin oligomers (from monomer to decamers) and polymers, with polymers being the predominant component (26.4%, w/w). Different CPs–gelatin–chitosan mass ratios were tested to investigate the effects of formulation on the nanoparticle fabrication. Using CPs–gelatin–chitosan mass ratio of 0.75:1:0.5, the resultant nanoparticles had a particle size of 344.7nm, zeta-potential of +29.8mV, particle yield of 51.4%, loading efficiency of 50.1%, and loading capacity of 20.5%. The CPs–gelatin–chitosan nanoparticles were spherical as observed by scanning electron microscopy (SEM). Fourier transform infrared spectroscopy (FTIR) suggested that the primary interaction between the CPs and gelatin was hydrogen bond and hydrophobic interaction, while electrostatic interaction was the main binding force between chitosan and CPs–gelatin nanoparticles. Nanoencapsulation of the CPs significantly improved the stability of the CPs at 60°C. The CPs–gelatin–chitosan nanoparticles showed the same apoptotic effects at lower concentrations in human acute monocytic leukemia THP-1 cells compared with the CPs in solution.

Mesenchymal stem cells associated with porous chitosan–gelatin scaffold: A potential strategy for alveolar bone regeneration

Tissue engineering has emerged as a novel treatment for replacement of lost bone tissue. This study evaluated the effects of a chitosan-gelatin scaffold seeded with bone marrow mesenchymal stem cells (BMMSCs) in the healing process of tooth sockets in rats. BMMSCs isolated from transgenic rats expressing enhanced green fluorescent protein (eGFP) were expanded and seeded on a chitosan-gelatin scaffold. These constructs were cultured for three days and characterized by scanning electronic microscopy (SEM) and energy dispersion spectroscopy (EDS). Receptor rats received the implant in the left sockets, after upper first-molar extraction. Right alveoli served as control. Animals were sacrificed at days 5, 21, and 35 post-graft for examination. Morphometry demonstrated increased bone mineralization after 21 and 35 days in transplanted sockets. Migration, differentiation, and fate of eGFP-labeled BMMSCs were monitored by immunohistochemistry. Tartrate-resistant acid phosphatase staining (TRAP) was carried out at 21 days, to identify the involvement of osteoclastic cells in the scaffold resorption. The biomaterial was resorbed by TRAP-negative giant cells in a typical foreign body reaction. Immunohistochemical findings showed that BMMSCs contributed to bone, epithelial, and vascular repair. Together, results indicate that BMMSCs loaded in the chitosan-gelatin scaffold is a strategy for tissue development in bone engineering.

Quantitative characterization of the electrospun gelatin–chitosan nanofibers by coupling scanning electron microscopy and atomic force microscopy

Nanofibers were electrospun from gelatin and chitosan at different mass ratios (gelatin/chitosan: 0/100, 25/75, 50/50, 75/25, 100/0). Atomic force microscopy (AFM) combined with scanning electron microscopy (SEM) was utilized in this study to evaluate the morphological and mechanical properties of the gelatin–chitosan nanofibers. The SEM images showed that the electrospun gelatin–chitosan nanofibers possessed more uniform morphologies than the pure gelatin or chitosan nanofibers. Moreover, AFM-HarmoniX mode was used to quantitatively assess the Derjaguin–Müller–Toporov (DMT) modulus of gelatin–chitosan nanofibers. After modified by two correction factors, the DMT modulus of gelatin–chitosan nanofibers showed higher values than the pure gelatin or chitosan nanofibers, which indicated the existence of intermolecular interaction within the electrospun gelatin–chitosan nanofibers.

Determination and comparison of specifics of nucleus pulposus cells of human intervertebral disc in alginate and chitosan-gelatin scaffolds

Introduction:Low back pain is a major economical and social problem nowadays. Intervertebral disc herniation and central degeneration of disc are two major reasons of low back pain that occur because of structural impairment of disc. The intervertebral disc contains three parts as follows : Annulus fibrosus, transitional region, and nucleus pulposus, which forms the central nucleus of the disc. The reduction of cell count and extracellular matrix, especially in nucleus pulposus, causes disc degeneration. Different scaffolds (natural and synthetic) have been used for tissue repairing and regeneration of the intervertebral disc in tissue engineering. Most scaffolds have biodegradable and biocompatible characteristics and also prepare a fine condition for proliferation and migration of cells. In this study, proliferation of NP cells of human intervertebral disc compromised in Chitosan-gelatin scaffold with alginate scaffold was studied.Materials and Methods:NP cells derived from nucleus pulposus by collagenase enzymatic hydrolysis. They were derived from patients who undergoing open surgery for discectomy in the Isfahan Alzahra hospital. Chitosan was blended with gelatin and glutaraldehyde was used for cross linking the two polymers. Then, alginate scaffold was prepared. Cellular suspension with 1 × 105 transferred to each scaffold and cultured for 21 days. Cell viability and proliferation investigated by trypan blue and (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Scanning electron microscope (SEM) was used to assert the porosity and to survey structure of scaffold.Results:MTT assay dem1onstrated that cell viability of third day had significant difference in contrast by first day in both scaffolds. Accordingly, there was a significant decreased in cellular viability from day 3 to 21. Results of the cell count showed a punctual elevation cell numbers for alginate scaffold but there was no similar result for chitosan–gelatin scaffold.Conclusion:Alginate scaffold prepared a better condition for proliferation of NP cells in comparison with chitosan–gelatin scaffold. Results of this study suggest that alginate scaffold could be useful in in vivo studies and treatment.

Assessing viscoelastic properties of chitosan scaffolds and validation with cyclical tests

We evaluated and modeled the viscoelastic characteristics of chitosan and chitosan–gelatin scaffolds prepared using a freeze-drying technique. Chitosan and chitosan–gelatin solutions (0.5 and 2wt.%) were frozen at −80°C and freeze-dried. Using the scaffolds, uniaxial tensile properties were evaluated under physiological conditions (hydrated in phosphate buffered saline at 37°C) at a cross-head speed of 0.17mms−1 (10mmmin−1). From the break strain, the limit of strain per ramp was calculated to be 5% and the samples were stretched at a strain rate of 2.5%s−1. The ramp-and-hold type of stress-relaxation test was performed for five successive stages. Chitosan and chitosan–gelatin showed nearly 90% relaxation of stress after each stage. The relaxation behavior was independent of the concentration of chitosan and gelatin. Also, changes in the microstructure of the tested samples were evaluated using an inverted microscope. The micrographs acquired after relaxation experiments showed orientation of pores, suggesting the retention of the stretched state even after many hours of relaxation. Based on these observations, two models (i) containing a hyper-elastic spring (containing two parameters) and (ii) retaining pseudo-components (containing three parameters) were developed in Visual Basic Applications accessed through MS Excel. The models were used to fit the experimental stress-relaxation data and the parameters obtained from modeling were used to predict their respective cyclic behaviors, which were compared with cyclical experimental results. These results showed that the model could be used to predict the cyclical behavior under the tested strain rates. The model predictions were also tested using cyclic properties at a lower strain rate of 0.0867%s−1 (5%min−1) for 0.5wt.% scaffolds but the model could not predict cyclical behavior at a very slow rate. In summary, the pseudo-component modeling approach can be used to model the sequential strain-and-hold stage and predict cyclical properties for the same strain rate.

Increased matrix synthesis by fibroblasts with decreased proliferation on synthetic chitosan–gelatin porous structures

Influence of mechanical characteristics and matrix architecture of substrates used in cell culture is an important issue to tissue engineering. Chitosan-based materials have been processed into porous structures, injectable gels and membranes, and are investigated to regenerate various tissues. However, the effect of these structures on cell growth and matrix production in accordance with each of the differing scaffolds has not been examined. We investigated the influence of porous structures, hydrogels, and membranes on the growth of normal human fibroblasts and their matrix production in a serum-free system. We used chitosan alone and in combination with gelatin. Injectable hydrogels were prepared using 2-glycerol phosphate. From the same solution, porous scaffolds and membranes were formed using controlled rate freezing and lyophilization, and air-drying, respectively. Fibroblast growth was evaluated on the 4th and 10th days using flow cytometry and CFDA-SE pre-staining. Cell morphology was assessed using actin and nucleus staining. Total protein content, collagen, tropoelastin, and MMP2/MMP-9 activity in the media supernatant were assessed by BCA, Sircol™, Fastin Elastin, and fluorogeneic peptide assays. Collagen accumulated in the matrix was assessed by Sircol™ assay after pepsin/acetic acid digestion and by Masson's Trichrome staining. These results showed increased viability of fibroblasts on chitosan-gelatin porous scaffold with decreased proliferation relative to tissue culture plastic (TCP) surface despite the cells showing spindle shape. The total protein, collagen, and tropoelastin contents were higher in the spent media from chitosan-gelatin porous scaffolds compared to other conditions. MMP2/MMP9 activity was comparable to TCP. An increase in collagen content was also observed in the matrix, suggesting increased matrix deposition. In summary, matrix production is influenced by the form of chitosan structures, which significantly affects the regenerative process.

Preparation and characterization of nano hydroxyapatite/polymeric composites materials. Part I

The present study is focused on preparation of nano composite materials and the effect of citric acid on their different properties. The formation of nano HA and its interaction with chitosan (C), gelatin (G) polymers and citric acid (CA) materials were studied. The Fourier Transformed Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize these composite materials. The compressive strength (CS) was also measured to know the reinforcement of the prepared composites. The results show that carboxylic and amino groups play crucial role for HA formation on chitosan–gelatin polymeric matrix in the presence of citric acid (CA). The formation of nano HA particles and its average size of crystallite is increased with increase of CG content and decreased with addition of CA. Also, the HA formation and binding strength between its particles are improved into the composites especially with CA. The nano-composites containing the best ratio of nHA (70%) with CA (0.2 M) are promising for medical applications in the future.

Covalent and ionic co‐cross‐linking—An original way to prepare chitosan–gelatin hydrogels for biomedical applications

The first goal of this work was to develop a method for obtaining interpenetrating gelatin (G)-chitosan (CS) networks prepared by double cross-linking (covalent followed by ionic) that exhibit hydrogel character. The second goal was to modulate their properties as a function of the preparation parameters by using neural network models. This study was therefore carried out by experiment and simulation. The covalent cross-linking resulted from the reaction between the carbonyl groups of glutaraldehyde with amino groups belonging to both polymers; the ionic cross-linking is based on the interaction between tripolyphosphate anions and protonated amine groups (ammonium ions) of the polymers. The total cross-linking density (indirectly assessed by estimating the water swelling capacity) and the ability to include hydrosoluble bioactive principles are influenced by the following process parameters: the CS/G ratio, the amount of ionic cross-linker, and the ionic cross-linking time. The prepared hydrogels were characterized with respect to their structural, morphological, and some physical properties. The hydrogels ability to load high amounts of water-soluble drugs indicates their potential use as carriers for biologically active principles in the human body. A neural network methodology was applied to model the swelling degree and caffeine loading/release capacity depending on reaction conditions; in addition, applying this method, the optimal preparation conditions have been determined, targeting pre-established values for swelling degree or maximum caffeine value. The accuracy of the results obtained through this technique proves that the neural networks are suitable tools for modeling cross-linking processes taking place complex nonlinear polymers.

Incorporation of PLGA nanoparticles into porous chitosan–gelatin scaffolds: Influence on the physical properties and cell behavior

Bone regeneration can be accelerated by localized delivery of appropriate growth factors/biomolecules. Localized delivery can be achieved by a 2-level system: (i) incorporation of biomolecules within biodegradable particulate carriers (nanoparticles), and (ii) inclusion of such particulate carriers (nanoparticles) into suitable porous scaffolds. In this study, freeze-dried porous chitosan–gelatin scaffolds (CH–G: 1:2 ratio by weight) were embedded with various amounts of poly(lactide-co-glycolide) (PLGA) nanoparticles, precisely 16.6%, 33.3% and 66.6% (respect to CH–G weight). Scaffolds loaded with PLGA nanoparticles were subjected to physico-mechanical and biological characterizations including morphological analysis, swelling and dissolution tests, mechanical compression tests and cell viability tests. Results showed that incorporation of PLGA nanoparticles into porous crosslinked CH–G scaffolds: (i) changed the micro-architecture of the scaffolds in terms of mean pore diameter and pore size distribution, (ii) reduced the dissolution degree of the scaffolds, and (iii) increased the compressive modulus. On the other hand, the water uptake behavior of CH–G scaffolds containing PLGA nanoparticles significantly decreased. The incorporation of PLGA nanoparticles did not affect the biocompatibility of CH–G scaffolds.

Biomimetic multicomponent polysaccharide/nano-hydroxyapatite composites for bone tissue engineering

Nano-hydroxyapatite/chitosan–pectin (nHCP) composite was prepared via mineralization of a chitosan–pectin network. Then nHCP/chitosan–gelatin (nHCP/CG) scaffolds were prepared via the blending of nHCP and chitosan–gelatin solution. Results suggested that nHCP/CG scaffolds have appropriate porosity, water absorption ability and degradation behaviors. nHCP can be fused into the pore wall of nHCP/CG scaffold via chemical crosslinking interactions, which avoids the agglomeration and migration of nHA particles. Moreover, the compressive strength of nHCP/CG scaffold ranges from 10.4±1.64 to 13.5±3.85MPa. nHCP/CG scaffolds have stable physical and chemical structures, which can provide appropriate microenvironments for cells to attach and proliferate for MC 3T3-E1 cells. Therefore, nHCG/CG is a potential biomaterial in bone tissue engineering.

Effects of gelatin origin, bovine-hide and tuna-skin, on the properties of compound gelatin–chitosan films

With the purpose to improve the physico-chemical performance of plain gelatin and chitosan films, compound gelatin–chitosan films were prepared. The effect of the gelatin origin (commercial bovine-hide gelatin and laboratory-made tuna-skin gelatin) on the physico-chemical properties of films was studied. The dynamic viscoelastic properties (elastic modulus G′, viscous modulus, G″ and phase angle) of the film-forming solutions upon cooling and subsequent heating revealed that the interactions between gelatin and chitosan were stronger in the blends made with tuna-skin gelatin than in the blends made with bovine-hide gelatin. As a result, the fish gelatin–chitosan films were more water resistant (∼18% water solubility for tuna vs 30% for bovine) and more deformable (∼68% breaking deformation for tuna vs 11% for bovine) than the bovine gelatin–chitosan films. The breaking strength of gelatin–chitosan films, whatever the gelatin origin, was higher than that of plain gelatin films. Bovine gelatin–chitosan films showed a significant lower water vapour permeability (WVP) than the corresponding plain films, whereas tuna gelatin–chitosan ones were only significantly less permeable than plain chitosan film. Complex gelatin–chitosan films behaved at room temperature as rubbery semicrystalline materials. In spite of gelatin–chitosan interactions, all the chitosan-containing films exhibited antimicrobial activity against Staphylococcus aureus, a relevant food poisoning. Mixing gelatin and chitosan may be a means to improve the physico-chemical performance of gelatin and chitosan plain films, especially when using fish gelatin, without altering the antimicrobial properties.

Cross-Linking of Gelatin and Chitosan Complex Nanofibers for Tissue-Engineering Scaffolds

The aim of this study is to investigate cross-linked gelatin–chitosan nanofibers produced by means of electrospinning. Gelatin and chitosan nanofibers were electrospun and then cross-linked by glutaraldehyde (GTA) vapor at room temperature. Scanning electron microscopy (SEM) images showed that the cross-linked mats could keep their nanofibrous structure after being soaked in deionized water at 37° C. The cross-linking mechanism was discussed based on FT-IR results. The two main mechanisms of cross-linking for chitosan and gelatin–chitosan complex are Schiff base reaction and acetalization reaction. For gelatin, the mechanism of cross-linking was Schiff base reaction. The mechanical properties of nanofibrous mats were improved after cross-linking. The biocompatibility of electrospun nanofibrous mats after cross-linking was investigated by the viability of porcine iliac endothelial cells (PIECs). The morphologies of PIECs on the cross-linked nanofibrous mats were observed by SEM. In addition, proliferation of PIECs was tested with the method of methylthiazol tetrazolium (MTT) assay. The results indicate that gelatin–chitosan nanofibrous mats could be a promising candidate for tissue-engineering scaffolds.

Human PDL Fibroblasts Proliferation in Scaffolds on Bioactive Glass Modified Ceramics

Scaffolds are commonly used as cell’s vehicles in order to promote cell development. The aim of this study was to investigate the proliferation of human periodontal ligament fibroblasts (PDLF) in composite ceramic scaffolds. Chitin (CHN), chitosan (CHS) and chitosangelatin (CH-G) scaffolds were fabricated on the surface of ceramic disks, coated with a mixture of a bioactive glass modified ceramic. Cell proliferation was evaluated with the MTS method. All composite ceramic scaffolds were successfully loaded with PDLF cells. However, only in CH-G composite ceramicscaffolds cell population progressively increased until day 7 and presented a sudden drop at day 10 before being stabilized for the rest of the testing period. In the case of CHN and CHS the cell number was progressively decreasing. The successful observed cellular response in CH-G composite ceramic scaffolds could support the development of a protocol for tissue engineering on the materials used.

BIOMIMETIC ELECTROSPUN GELATIN–CHITOSAN POLYURETHANE FOR HEART VALVE LEAFLETS

Native heart valve leaflets are subjected to continuous pulsatile and homodynamic forces and can be as thin as 300 μm. For a proper function of the valve the materials selected for the leaflets need to be biocompatible, robust, flexible, and have comparable mechanical properties to the natural ones.In this paper, biocompatibility and cell retention ability for gelatin–chitosan polyurethane (PU), polyglycolide (PGA)/PLA and collagen-coated bovine pericardium were examined and their mechanical properties were tested. Endothelial cells, isolated from ovine carotid arteries were seeded onto these materials and exposed to a range of shear-stresses for a period of 1–3 h.The findings indicated that throughout the exposure time and the shear-stress range tested, a mean cell retention rate of 80% was obtained in the gelatin–chitosan PU group. However, for PGA/PLA and pericardium groups it was found that as the exposure time of shear-stress increased, a significant cell reduction was observed. Noticeably for all the range of physiological flow conditions tested, the electrospun gelatin–chitosan PU demonstrated good biocompatibility and cell retention properties and could be potentially used as a biomaterial for tissue engineering of heart valves.

Inverted colloidal crystal scaffolds with laminin-derived peptides for neuronal differentiation of bone marrow stromal cells

This study presents the effect of pore regularity on the preservation and differentiation of bone marrow stromal cells (BMSCs). Scaffolds with interconnected pores of inverted colloidal crystal (ICC) geometry were prepared by infiltrating chitosan–gelatin gels into the interstices of self-assembled microspheres, which were later dissolved with a solvent. In addition, the pore surfaces were grafted with two laminin-derived peptides (LDP). The experimental results revealed that the number of BMSCs in ICC scaffolds could increase 2.7-fold after cultivation over 7 days. Moreover, the distribution of cultured BMSCs in ICC scaffolds was quite uniform as compared with freeform scaffolds. ICC scaffolds could preserve 63% phenotypic BMSCs in average and freeform scaffolds 56%. The grafted LDP enhanced the adhesion efficiency of BMSCs in ICC scaffolds (about 70–75%) and produced NeuN-positive cells. A further induction with neuron growth factor could guide the differentiation of BMSCs toward mature neurons in LDP-grafted ICC scaffolds. The controlled topography of ICC structure and surface LDP can be promising in the cultivation of BMSCs and neural regeneration.

Preparation and evaluation of chitosan-gelatin composite scaffolds modified with chondroitin-6-sulphate

Abstract The objective of the present study was to investigate the properties of porous chitosan–gelatin scaffolds. The modification of samples was done by incorporation of chondroitin-6-sulphate in bulk phase through cross linking with glutaraldehyde. Scaffolds were prepared using the freeze-drying method. An in vitro cell culture of fibroblasts L-929 was employed to study the growth and attachment of cells to the scaffolds. Optical microscopy showed high cell density for the sample supplemented with chondroitin-6-sulphate. Scanning electron microscopy was used to analyze the growth and attachment of cells. Results of the tests revealed that the sample with a 65: 35 ratio of gelatin and chitosan was suitable for both cell attachment and proliferation in fibroblast cultures. The cell viability 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) assay with human mesenchymal stem cells on the previous sample showed about 80 % increase in cell viability. To analyze the mechanical properties of scaffolds, the tensile strengths of the samples were measured and all samples showed stress at break above 0.1 MPa. Optimum substratum composition for porous scaffolds would involve a compromise between the desired attributes of biocompatibility, promotion of cell growth and mechanical strength.