Kinds Of Biomaterials Research Articles

Evaluation of cell adhesion and osteoconductivity in bone substitutes modified by polydopamine.

Bones damaged due to disease or accidents can be repaired in different ways. Tissue engineering has helped with scaffolds made of different biomaterials and various methods. Although all kinds of biomaterials can be useful, sometimes their weakness in cellular activity or osteoconductivity prevents their optimal use in the fabrication of bone scaffolds. To solve this problem, we need additional processes, such as surface modification. One of the common methods is coating with polydopamine. Polydopamine can not only cover the weakness of the scaffolds in terms of cellular properties, but it can also create or increase osteoconductivity properties. Polydopamine creates a hydrophilic layer on the surface of scaffolds due to a large number of functional groups such as amino and hydroxyl groups. This layer allows bone cells to anchor and adheres well to the surfaces. In addition, it creates a biocompatible environment for proliferation and differentiation. Besides, the polydopamine coating makes the surfaces chemically active by catechol and amine group, and as a result of their presence, osteoconductivity increases. In this mini-review, we investigated the characteristics, structure, and properties of polydopamine as a modifier of bone substitutes. Finally, we evaluated the cell adhesion and osteoconductivity of different polydopamine-modified bone scaffolds.

3D Printed Composite Scaffolds in Bone Tissue Engineering: A Systematic Review.

This study aimed to analyze the effect of fabrication factors on both biological and physico-chemical features of 3-dimensional (3D) printed composite scaffolds. Electronic search was done according to the PRISMA guideline in PubMed and Scopus databases limited to English articles published until May 2021. Studies in which composite scaffolds were fabricated through computer-aided design and computer-aided manufacturing (CADCAM)- based methods were included. Articles regarding the features of the scaffolds fabricated through indirect techniques were excluded. Full text of 121 studies were reviewed, and 69 met the inclusion criteria. According to analyzed studies, PCL and HA were the most commonly used polymer and ceramic, respectively. Besides, the solvent-based technique was the most commonly used composition technique, which enabled preparing blends with high concentrations of ceramic materials. The most common fabrication method used in the included studies was Fused Deposition Modeling (FDM). The addition of bio-ceramics enhanced the mechanical features and the biological behaviors of the printed scaffolds in a ratio-dependent manner. However, studies that analyzed the effect of ceramic weight ratio showed that scaffolds with the highest ceramic content did not necessarily possess the optimal biological and non-biological features. The biological and physico-chemical behaviors of the scaffold can be affected by pre-printing factors, including utilized materials, composition techniques, and fabrication methods. Fabricating scaffolds with high mineral content as of the natural bone may not provide the optimal condition for bone formation. Therefore, it is recommended that future studies compare the efficiency of different kinds of biomaterials rather than different weight ratios of one type.

The Role of the Sol-Gel Synthesis Process in the Biomedical Field and Its Use to Enhance the Performance of Bioabsorbable Magnesium Implants

In the present day, the increment in life expectancy has led to the necessity of developing new biomaterials for the restoration or substitution of damaged organs that have lost their functionalities. Among all the research about biomaterials, this review paper aimed to expose the main possibilities that the sol-gel synthesis method can provide for the fabrication of materials with interest in the biomedical field, more specifically, when this synthesis method is used to improve the biological properties of different magnesium alloys used as biomaterials. The sol-gel method has been widely studied and used to generate ceramic materials for a wide range of purposes during the last fifty years. Focused on biomedical research, the sol-gel synthesis method allows the generation of different kinds of biomaterials with diverse morphologies and a high potential for the biocompatibility improvement of a wide range of materials commonly used in the biomedical field such as metallic implants, as well as for the generation of drug delivery systems or interesting biomaterials for new tissue engineering therapies.

Controllable growth of spiral ganglion neurons by magnetic colloidal nanochains

Nerve regeneration based on neural stem cell therapy has become a promising cure for neurological disorders in recent decades. Various kinds of biomaterials have been developed to guide the oriented growth of newborn neurites, which is the fundamental factor to the synaptic connection of newly differentiated neurons with the desired partners during the regeneration. However, the applied biomaterials are usually incapable of guidance with multiple directions, besides, the underlying guiding mechanism has yet to be clearly stated. In this paper, a novel guiding approach based on the magnetic colloidal nanochains was designed for the oriented growth of newborn neurites. The magnetic colloidal nanochains with aligned topography were fabricated from the self-assembly of the magnetic colloidal nanoparticles under the magnetic field. Well orientation of the newborn neurites from the seeded spiral ganglion neurons (SGNs) was found along the nanochains, which induced the alignment of the seeded SGNs. In addition, the growth cone development and synapse formation of the seeded SGNs was promoted under the guidance of the nanochains, which possessed important significance in the rearrangement of nerve network and recovery of neural signal communication during the regeneration. Importantly, the multidirectional nanochains could be constructed by regulating the magnetic field, which contributed to the oriented guidance of SGNs alignment with multiple directions. This feature facilitated to the complex regenerate environment of the nervous system in vitro. Furthermore, the underlying guiding mechanism was revealed by the transcriptome analysis, which showed well consistent with the “contact guidance” of the nanochains. Thus, it was demonstrated that the magnetic colloidal nanochains possessed huge value in biomedical applications.

Histologic and Immunohistochemical Assessment of the Effect of Various Biomaterials on New Bone Formation in the Maxillary Sinus Floor Augmentation Procedure.

To assess the effect of different kinds of biomaterials placed with maxillary sinus floor augmentation (MSFA) on bone regeneration. Thirty-six New Zealand rabbits were used in the study. A standardized method of surgical approach was used for MSFA under anesthesia in all groups. The procedure was performed for each animal. Six separate groups with 12 cases were created. In group 1, no graft was used in MSFA. Advanced platelet-rich fibrin (A-PRF), absorbable collagen cone (ACC), venous blood, the combination of ACC and platelet-rich plasma (PRP), and the combination of ACC and enamel matrix derivative (EMD) were used in groups 2, 3, 4, 5, and 6, respectively. At the end of 4 and 12 weeks, three rabbits from each group were sacrificed by applying high-dose anesthetic, and samples were examined histologically and immunohistochemically. Groups 2 and 5 showed significantly increased new bone formation compared with groups 1 and 4, 4 weeks after MSFA (P < .05). Twelve weeks after sinus floor augmentation, groups 2, 3, 5, and 6 showed significantly higher new bone formation than group 1 (P < .05). Groups 2 and 5 showed significantly higher hard tissue response than groups 1 and 4 at the end of 4 weeks (P < .05). Groups 5 and 6 demonstrated significantly higher hard tissue response than group 1 at the end of 12 weeks (P < .05). Group 5 also showed significantly higher hard tissue response than group 4 at the end of 12 weeks (P < .05). Immunohistochemical analysis showed a significant difference between the osteocalcin scores of groups 2 and 4 and group 1 at the end of 4 and 12 weeks (P < .05). There was also a statistically significant difference between osteocalcin scores at 4 and 12 weeks for groups 1 and 5 (P < .05). When osteopontin scores were compared, there was no significant difference between groups at 4 and 12 weeks (P > .05). Groups 1, 2, and 5 showed significant changes in osteopontin scores between 4 and 12 weeks (P < .05). The combination of ACC and PRP and the combination of ACC and EMD showed increased new bone formation and hard tissue response. A-PRF also showed promising results in new bone formation at the end of both 4 and 12 weeks. The usage of ACC as a carrier for liquid-form biomaterials may be more beneficial than the usage of ACC alone.

Preparation and biodegradable properties of hydroxyapatite nanoparticle composite coated with poly lactic-co-glycolic acid/polyvinyl alcohol for bone regeneration.

Bone loss rapidly increases 6 months post tooth extraction, which causes the atrophy of the alveolar bone. Two kinds of biomaterials which can stimulate bone regeneration are bioceramics and polymers. Making a composite of biomaterials results in better physical and biomolecular characteristics in comparison with a bioceramic or a polymer alone. Hydroxyapatite nanoparticles (HANPs) are one of the bioceramics commonly used for bone regeneration; they can degrade faster than hydroxyapatite (HA) microparticles, but have an insufficient pore size. Polyvinyl alcohol (PVA) and poly lactic-co-glycolic acid (PLGA) are polymers which have been used for biomedical applications. However, PLGA alone has insufficient cell attachment and PVA alone slowly degrades in the bone tissue. The aim of the present study was to analyze the biodegradation properties of the HANP/PLGA/PVA composites and investigate the pore size. The HANP/PLGA/PVA composites were prepared using the freeze-drying method, with 20% (w/w) of HANP and 20% (w/w) of PLGA. Morphology and the pore size were determined by means of the field emission scanning electron microscopy (FE-SEM) analysis. Biodegradation properties were determined by calculating water uptake and water loss for 1, 3 and 6 weeks. Statistical analysis was performed based on the one-way analysis of variance (ANOVA) at p < 0.05. The HANP/PLGA/PVA composites had the greatest mean pore size and a rougher surface than others (176.00 ±61.93 μm; p < 0.05). Moreover, the HANP/PLGA/PVA composites had the greatest water uptake, significantly in the 3rd (730.46%; p < 0.05) and 6th weeks (731.07%; p < 0.05), and water loss in the 6th week (67.69%; p < 0.05). The HANP/PLGA/PVA composites have optimal pore size, morphology and degradability, which shows their high potential as an effective bone scaffold to repair the alveolar defect post tooth extraction.

Theanine-Modified Graphene Oxide Composite Films for Neural Stem Cells Proliferation and Differentiation

The central nervous system (CNS) injury has been a worldwide clinical problem for regenerative medicine. Nerve tissue engineering is a new strategy for CNS injury. Among kinds of biomaterials, graphene oxide (GO)-based degradable composite materials are considered to be promising in the field of neurogenesis. In this study, GO and L-theanine (TH) were combined by chemical grafting to prepare a new PLGA/GO-TH composite material. X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier-transform infrared spectra (FTIR), contact angle testers, and mechanical testers were performed to obtain characterization of composite materials. The protein adsorption efficiency of the PLGA/GO-TH films was then evaluated. Next, the effect of the composite films on neural stem cell (NSC) survival, proliferation, and differentiation was investigated. Our results indicated that L-theanine was successfully grafted onto GO. PLGA/GO-TH composite film can significantly improve NSC survival, proliferation, and neuronal differentiation. Our results demonstrated that the neurogenesis function of a novel PLGA/GO-TH composite film and its potential as a carrier for the further application in the CNS injury.

Effect of Alkaline Treatment on Characteristics of Bio-Calcium and Hydroxyapatite Powders Derived from Salmon Bone

Alkaline treatment has been extensively implemented in the extraction process of hydroxyapatite (HAp) extraction from various kinds of bio-materials, such as animal bone and scales. The main purpose of such treatment is to remove proteinaceous substances from raw materials. The influence of the alkaline treatment that could alter not only the organic contents but also chemical composition—specifically the Ca/P mole ratios of bio-calcium, HAp, and the biphasic apatite powders derived from salmon bone, a by-product from the salmon industry—was investigated. Both HAp and biphasic apatite powders were obtained from the calcination of bio-calcium powders with and without alkaline treatment, respectively. An X-ray diffraction analysis confirmed the presence of hydroxyapatite and β-tricalcium phosphate (β-TCP) in the calcined bone powder without alkaline treatment while only a single phase of hydroxyapatite was observed in the alkaline-treated sample. Calcium and phosphorus contents were measured by an inductively coupled plasma optical emission spectrometer (ICP-OES). A variation of Ca/P ratios was observed among all samples, depending on the chemical and heat treatment conditions. Organic molecules, such as protein, fat, hydroxyproline, and TBARS, were significantly lowered in bio-calcium powders with the alkaline treatment. This work represents important research on chemical treatment prior to the raw material conversion process, which significantly influences chemical and phase compositions of the bio-calcium and hydroxyapatite powder derived from salmon bone waste.

Preparation and Characterization of a Novel Triple Composite Scaffold Containing Silk Fiborin, Chitosan, and Alginate for 3D Culture of Colonic Carcinoma Cells In Vitro.

BackgroundThree-dimensional (3D) cell-culture scaffolds are ideal in vitro models to bridge the gap between two-dimensional cell culture in vitro and in vivo cancer models. Construction of 3D scaffolds using two kinds of biomaterials has been reported, but there are still many defects. To improve the performance of the scaffolds for 3D cell culture of colonic carcinoma (CC) cells in vitro, we attempted to construct triple composite scaffolds using silk fibroin (SF), chitosan (Cs), and alginate (Alg).Material/MethodsWe explored the suitability of triple composite scaffolds of SF/Cs/Alg at ratios of 1: 1: 0.5, 1: 1: 1, and 1: 1: 2 for 3D culture of CC cells, and used the dual composite scaffold of SF/Cs (1: 1) as a control group. We analyzed the physicochemical characteristics of these scaffolds and studied cell adhesion, cell proliferation, migration, colony-forming ability, microstructure and ultrastructure, and spheroid-forming capacity of the commercially available CC cell line HCT-116 on the prepared scaffolds.ResultsOur results show that SF/Cs/Alg (1: 1: 1) scaffolds demonstrated the best profile, the highest uniform porosity and connectivity, and excellent hydroscopicity, and also exhibited appropriate and controlled swelling and degradation characteristics. The adhesion, proliferation, colony-forming, and wound-healing assays, green fluorescent protein-labeled HCT116 cell imaging, 4′,6-diamidino-2-phenylindole and DY-554-phalloidin staining, scanning electron microscopy, and haematoxylin and eosin staining revealed that the triple composite scaffolds of SF/CS/Alg (1: 1: 1) supported cell adhesion, proliferation, migration, colony-forming ability, and spheroid formation far better than the dual composite scaffold of SF/CS (1: 1).ConclusionsThis study successfully demonstrated the potential of SF/Cs/Alg (1: 1: 1) scaffold as an alternative for the 3D in vitro culture of CC cells.

Substrate Independent Liquid Phase Epitaxy of HKUST‐1 as Anticoagulant and Antimicrobial Coating

AbstractThe effective deposition of metal–organic frameworks on kinds of biomaterials is still challenging and highly desirable. Using polydopamine as the effective nucleation center, HKUST‐1 is successfully prepared on three kinds of inert biomaterials, i.e., titanium oxide film (Ti–O), 316L stainless steel (316L SS), and poly(vinyl chloride) (PVC). Characterization of the surfaces by powder X‐ray diffraction confirm the oriented crystal growth of HKUST‐1 on the polydopamine coated substrates. There are no significant difference in catalytical NO generation and surface copper content of the three samples with HKUST‐1 deposition. All keep a NO release speed of ≈2.5 × 10−10 mol cm−2 min−1, thus platelet activation on the HKUST‐1 modified surfaces are inhibited compared to that of the unmodified ones. Ex vivo test shows thrombi formation is dramatically reduced. The HKUST‐1 coated surfaces elicit 95% reduction in the bacterial attachment of both Staphylococcus aureus and Escherichia coli. The endothelial cells and macrophages culture results support good biocompatibility of the modified surfaces. It provides a promising, facile, and effective approach for surface modification of blood contact biomaterials.

Spheroid Culture System Methods and Applications for Mesenchymal Stem Cells.

Owing to the importance of stem cell culture systems in clinical applications, researchers have extensively studied them to optimize the culture conditions and increase efficiency of cell culture. A spheroid culture system provides a similar physicochemical environment in vivo by facilitating cell–cell and cell–matrix interaction to overcome the limitations of traditional monolayer cell culture. In suspension culture, aggregates of adjacent cells form a spheroid shape having wide utility in tumor and cancer research, therapeutic transplantation, drug screening, and clinical study, as well as organic culture. There are various spheroid culture methods such as hanging drop, gel embedding, magnetic levitation, and spinner culture. Lately, efforts are being made to apply the spheroid culture system to the study of drug delivery platforms and co-cultures, and to regulate differentiation and pluripotency. To study spheroid cell culture, various kinds of biomaterials are used as building forms of hydrogel, film, particle, and bead, depending upon the requirement. However, spheroid cell culture system has limitations such as hypoxia and necrosis in the spheroid core. In addition, studies should focus on methods to dissociate cells from spheroid into single cells.

Functional Protein-Based Bioinspired Nanomaterials: From Coupled Proteins, Synthetic Approaches, Nanostructures to Applications.

Protein-based bioinspired nanomaterials (PBNs) combines the advantage of the size, shape, and surface chemistry of nanomaterials, the morphology and functions of natural materials, and the physical and chemical properties of various proteins. Recently, there are many exciting developments on biomimetic nanomaterials using proteins for different applications including, tissue engineering, drug delivery, diagnosis and therapy, smart materials and structures, and water collection and separation. Protein-based biomaterials with high biocompatibility and biodegradability could be modified to obtain the healing effects of natural organisms after injury by mimicking the extracellular matrix. For cancer and other diseases that are difficult to cure now, new therapeutic methods involving different kinds of biomaterials are studied. The nanomaterials with surface modification, which can achieve high drug loading, can be used as drug carriers to enhance target and trigger deliveries. For environment protection and the sustainability of the world, protein-based nanomaterials are also applied for water treatment. A wide range of contaminants from natural water source, such as organic dyes, oil substances, and multiple heavy ions, could be absorbed by protein-based nanomaterials. This review summarizes the formation and application of functional PBNs, and the details of their nanostructures, the proteins involved, and the synthetic approaches are addressed.

The Biosorption Features of Cr (VI) Ions by Dried Biomass of a Facultative Anaerobic Bacillus cereus Strain Pf-1

Many studies were undertaken on the biosorption potential of different kinds of biomaterials. However, there is a paucity of data regarding the biosorption mechanism of Cr (VI) using dried cells. In our study, the removal of Cr (VI) from aqueous solution was investigated in a batch system by the dried biomass of a chromium-resistant bacterium isolated from activated sludge samples. Equilibrium and kinetic experiments were undertaken at various initial metal concentration, pH, and biosorbent dosage. Bacillus cereus biomass was characterized using Energy-Dispersive X-ray (EDX), Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Biosorption process was found to be pH dependent. The optimum pH was found to be 2.0. The Langmuir and Freundlich were considered to identify the isotherm that could better describe the equilibrium adsorption of Cr (VI) onto the biomass. Langmuir and Freundlich models fitted our experimental data. The suitability of the pseudo-first order and pseudo-second order kinetic models for the biosorption of Cr (VI) onto Bacillus cereus was also performed. The mechanism for the adsorption was studied by fitting the kinetic data with the Boyd plot and intra-particle diffusion model. External mass transfer was found to be the rate-determining step. Based on the ionic nature of the metal, the intra-particle diffusion and extent of film diffusion varied.

Polymer-Based Nanomaterials for Photothermal Therapy: From Light-Responsive to Multifunctional Nanoplatforms for Synergistically Combined Technologies.

Materials for the treatment of cancer have been studied comprehensively over the past few decades. Among the various kinds of biomaterials, polymer-based nanomaterials represent one of the most interesting research directions in nanomedicine because their controlled synthesis and tailored designs make it possible to obtain nanostructures with biomimetic features and outstanding biocompatibility. Understanding the chemical and physical mechanisms behind the cascading stimuli-responsiveness of smart polymers is fundamental for the design of multifunctional nanomaterials to be used as photothermal agents for targeted polytherapy. In this review, we offer an in-depth overview of the recent advances in polymer nanomaterials for photothermal therapy, describing the features of three different types of polymer-based nanomaterials. In each case, we systematically show the relevant benefits, highlighting the strategies for developing light-controlled multifunctional nanoplatforms that are responsive in a cascade manner and addressing the open issues by means of an inclusive state-of-the-art review. Moreover, we face further challenges and provide new perspectives for future strategies for developing novel polymeric nanomaterials for photothermally assisted therapies.

Biomimetic Scaffolds for Bone Tissue Engineering.

The use of biomimetic scaffolds for bone tissue engineering has been studied for a long time. Biomimetic scaffolds can assist and accelerate bone regeneration that is similar to that of authentic tissue, which represents the environment of cells in a living organism. Currently, numerous biomaterials have been reported for use as a biomimetic scaffold. This review focuses on the design of biomimetic scaffolds, kinds of biomaterials and methods used to fabricate biomimetic scaffolds, growth factors used with biomimetic scaffold for bone regeneration, mobilization of biological agents into biomimetic scaffolds, and studies on (pre)clinical bone regeneration from biomimetic scaffolds. Then, future prospects for biomimetic scaffolds are discussed.

Capacitively Coupled Resistivity Imaging for Biomaterial and Biomedical Applications

Imaging of electrical conductivity is a promising technique in biomedical field, which can reveal the impedance distribution within the region of interest. However, the contact measurement of traditional electrical impedance tomography (EIT) results in some challenging practical limitations on its applications. This paper introduces a novel capacitively coupled EIT to the biomaterial/biomedical field for resistivity imaging, and studies various aspects of this new contactless technique on practical applications. A 12-electrode experimental phantom is developed and the corresponding computational model is established to obtain the sensitivity matrix of the phantom. A hybrid image reconstruction method, which combines the Tikhonov regularization method and the simultaneous iterative reconstruction technique, is introduced to solve the inverse problem. In biomedical applications, the frequency-dependent conductivity aspect is very critical. Therefore, both the time-difference and frequency-difference imaging methods are investigated. A background calibration approach is proposed for the frequency-difference capacitively coupled EIT to overcome the frequency dependence of the background signal. Experiments were carried out with three kinds of biomaterials and three backgrounds with different conductivities. Results show the working principles and potential of the capacitively coupled EIT on biomaterial and biomedical applications.

3D bioprinting of urethra with PCL/PLCL blend and dual autologous cells in fibrin hydrogel: An in vitro evaluation of biomimetic mechanical property and cell growth environment.

Urethral stricture is a common condition seen after urethral injury. The currently available treatments are inadequate and there is a scarcity of substitute materials used for treatment of urethral stricture. The traditional tissue engineering of urethra involves scaffold design, fabrication and processing of multiple cell types. In this study, we have used 3D bioprinting technology to fabricate cell-laden urethra in vitro with different polymer types and structural characteristics. We hypothesized that use of PCL and PLCL polymers with a spiral scaffold design could mimic the structure and mechanical properties of natural urethra of rabbits, and cell-laden fibrin hydrogel could give a better microenvironment for cell growth. With using an integrated bioprinting system, tubular scaffold was formed with the biomaterials; meanwhile, urothelial cells (UCs) and smooth muscle cells (SMCs) were delivered evenly into inner and outer layers of the scaffold separately within the cell-laden hydrogel. The PCL/PLCL (50:50) spiral scaffold demonstrated mechanical properties equivalent to the native urethra in rabbit. Evaluation of the cell bioactivity in the bioprinted urethra revealed that UCs and SMCs maintained more than 80% viability even at 7days after printing. Both cell types also showed active proliferation and maintained the specific biomarkers in the cell-laden hydrogel. These results provided a foundation for further studies in 3D bioprinting of urethral constructs that mimic the natural urethral tissue in mechanical properties and cell bioactivity, as well a possibility of using the bioprinted construct for in vivo study of urethral implantation in animal model. The 3D bioprinting is a new technique to replace traditional tissue engineering. The present study is the first demonstration that it is feasible to create a urethral construct. Two kinds of biomaterials were used and achieved mechanical properties equivalent to that of native rabbit urethra. Bladder epithelial cells and smooth muscle cells were loaded in hydrogel and maintained sufficient viability and proliferation in the hydrogel. The highly porous scaffold could mimic a natural urethral base-membrane, and facilitate contacts between the printed epithelial cells and smooth muscle cells on both sides of the scaffold. These results provided a strong foundation for future studies on 3D bioprinted urethra.

Osteogenic differentiation of preosteoblasts on a hemostatic gelatin sponge.

Bone tissue engineering provides many advantages for repairing skeletal defects. Although many different kinds of biomaterials have been used for bone tissue engineering, safety issues must be considered when using them in a clinical setting. In this study, we examined the effects of using a common clinical item, a hemostatic gelatin sponge, as a scaffold for bone tissue engineering. The use of such a clinically acceptable item may hasten the translational lag from laboratory to clinical studies. We performed both degradation and biocompatibility studies on the hemostatic gelatin sponge, and cultured preosteoblasts within the sponge scaffold to demonstrate its osteogenic differentiation potential. In degradation assays, the gelatin sponge demonstrated good stability after being immersed in PBS for 8 weeks (losing only about 10% of its net weight and about 54% decrease of mechanical strength), but pepsin and collagenases readily biodegraded it. The gelatin sponge demonstrated good biocompatibility to preosteoblasts as demonstrated by MTT assay, confocal microscopy, and scanning electron microscopy. Furthermore, osteogenic differentiation and the migration of preosteoblasts, elevated alkaline phosphatase activity, and in vitro mineralization were observed within the scaffold structure. Each of these results indicates that the hemostatic gelatin sponge is a suitable scaffold for bone tissue engineering.

Studies regarding the mechanisms involved in tissue regeneration, due to application of biomaterials obtained via biotechnology

ABSTRACTThe processes of regeneration and repair tissues that occur under action of any substance are based on the effects determinated by this substance on some soluble mediators (cytokines, growth factors, pro-/anti-inflammatory agents) and on the macrophages involved in process. In this respect in this paper we will present an in vitro study of three kinds of biomaterials (P1, P2 and P3) obtained by submerged biosynthesis. These materials were synthesised using three strains of Monascus sp. The biocompatibility studies, performed with the three biomaterials on the adherent cells lines, type L929 murine fibroblast or RAW 264.7 murine macrophage, showed that only the biomaterial P1 is biocompatible. In the presence of biomaterial P2 or P3, the cell viability is under 70% and it is not depending on their concentration, meaning that these biomaterials are not biocompatible. In order to evaluate P1 biomaterial capacity to activate secretion of mediators involved in the process of tissue repair, for this biomaterial was determined the ability of inducing the secretion of VEGF (vascular endothelial growth factor) for the human monocyte THP-1 cells line. The results obtained in vitro have been confirmed that in the presence of biomaterial P1, the macrophages THP-1 adopt a profile associated with accelerating the process of tissue repair characterized by the absence of the secretion of pro-inflammatory cytokines (TNF-α, IL-6) respectively by the secretion of anti-inflammatory cytokines (IL-1RA).

Development of Hydrogel with Anti-Inflammatory Properties Permissive for the Growth of Human Adipose Mesenchymal Stem Cells

Skin wound repair requires the development of different kinds of biomaterials that must be capable of restoring the damaged tissue. Type I collagen and chitosan have been widely used to develop scaffolds for skin engineering because of their cell-related signaling properties such as proliferation, migration, and survival. Collagen is the major component of the skin extracellular matrix (ECM), while chitosan mimics the structure of the native polysaccharides and glycosaminoglycans in the ECM. Chitosan and its derivatives are also widely used as drug delivery vehicles since they are biodegradable and noncytotoxic. Regulation of the inflammatory response is crucial for wound healing and tissue regeneration processes; and, consequently, the development of biomaterials such as hydrogels with anti-inflammatory properties is very important and permissive for the growth of cells. In the last years, it has been shown that mesenchymal stem cells have clinical importance in the treatment of different pathologies, for example, skin injuries. In this paper, we describe the anti-inflammatory activity of collagen type 1/chitosan/dexamethasone hydrogel, which is permissive for the culture of human adipose-derived mesenchymal stem cells (hADMSC). Our results show that hADMSC cultured in the hydrogel are viable, proliferate, and secrete the anti-inflammatory cytokine interleukin-10 (IL-10) but not the inflammatory cytokine Tumor Necrosis Factor-alpha (TNF-α).