Different Kinds Of Biomaterials Research Articles

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.

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.

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.

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.

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).

Characterization of bone marrow mononuclear cells on biomaterials for bone tissue engineering in vitro.

Bone marrow mononuclear cells (BMCs) are suitable for bone tissue engineering. Comparative data regarding the needs of BMC for the adhesion on biomaterials and biocompatibility to various biomaterials are lacking to a large extent. Therefore, we evaluated whether a surface coating would enhance BMC adhesion and analyze the biocompatibility of three different kinds of biomaterials. BMCs were purified from human bone marrow aspirate samples. Beta tricalcium phosphate (β-TCP, without coating or coated with fibronectin or human plasma), demineralized bone matrix (DBM), and bovine cancellous bone (BS) were assessed. Seeding efficacy on β-TCP was 95% regardless of the surface coating. BMC demonstrated a significantly increased initial adhesion on DBM and β-TCP compared to BS. On day 14, metabolic activity was significantly increased in BMC seeded on DBM in comparison to BMC seeded on BS. Likewise increased VEGF-synthesis was observed on day 2 in BMC seeded on DBM when compared to BMC seeded on BS. The seeding efficacy of BMC on uncoated biomaterials is generally high although there are differences between these biomaterials. Beta-TCP and DBM were similar and both superior to BS, suggesting either as suitable materials for spatial restriction of BMC used for regenerative medicine purposes in vivo.

The biosorption of Cr(VI) ions by dried biomass obtained from a chromium-resistant bacterium

The biosorption potential of many different kinds of biomaterials has been widely studied. However, there is little data on the biosorption mechanism of Cr(VI) by dried biomass. So the bio-removal of Cr(VI) ions from aqueous solutions was investigated using dried biomass from a chromium-resistant bacterium. The bacterium was isolated from dewatered sludge samples that were obtained from a sewage treatment plant. Equilibrium and kinetic experiments were performed at different metal concentrations, pH values, and biosorbents dosages. The biomass was characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The functional groups in the Bacillus cereus biomass which may play a role in the biosorption process were identified by Fourier transform infrared spectroscopy. The biosorption process was found to be highly pH dependent and the optimum pH for the adsorption of Cr(VI) was 2.0±0.3 at 30±2 °C. The experimental data fit well with Langmuir and Freundlich models as well as a pseudo-second order kinetic model. The mechanism for the biosorption was also studied by fitting the kinetic data with an intra-particle diffusion model and a Boyd plot. External mass transfer was found to be the rate-determining step for the adsorption process. Biosorption could be an alternative mechanism besides bio-oxidation and bio-reduction for the bioremediation of heavy metals.

Dominant thermogravimetric signatures of lignin in cashew shell as compared to cashew shell cake

Dominant thermogravimetric signatures related to lignin were observed in cashew shell as compared to these signatures in cashew shell cake. The phenomenon of weakening of lignin from cashew shell to cashew shell cake was explained on the basis of changes in the activation energies. The pertinent temperature regimes responsible for the release of different constituents of both the bio-materials were identified and compared. The activation energies of cashew shell and cashew shell cake were compared using Kissinger-Akahira-Sunose method. Thermogravimetric profiling of cashew shell and cashew shell cake indicated that these were different kinds of bio-materials.

Polyester Fleeces used as an Artificial Interstitium Influence the Spatial Growth of Regenerating Tubules

In regenerative medicine the use of stem/progenitor cells is a valuable therapeutical option for the regeneration of diseased tissues and organs. However, the secure application of cell-based therapies for the treatment of renal failure requires exact information regarding the mechanisms of parenchyma development in combination with different kinds of biomaterials. Recently, we demonstrated that application of stem/progenitor cells in combination with a polyester fleece I-7 as an artificial interstitium supported the spatial generation of tubules during perfusion culture in chemically defined ®

Delayed reaction to the Dacron buttress used in Stamey bladder neck suspension

Stamey bladder neck suspension is thought to be an excellent procedure for stress urinary incontinence in selected groups of patients. However we must not ignore the complications of this procedure. We report a case of a patient who developed a delayed reaction with bladder wall erosion to the Dacron buttress used in Stamey urethropexy 19 years before. She was presented with pelvic pain and persisting irritative bladder symptoms. The treatment of choice was cystoscopic removal of suture and buttress. Tissue intolerance is a common problem with the use of different kinds of biomaterials in incontinence surgery. Careful cystourethroscopy is essential for early diagnosis and treatment if pain, infections and severe irritative symptoms occur postoperatively.

Growth of embryonic renal parenchyme at the interphase of a polyester artificial interstitium

The construction of an artificial kidney module by tissue engineering or the application of cell-based therapies for the treatment of renal failure requires exact information regarding the cellbiological mechanisms of parenchyme development in combination with different kinds of biomaterials. To learn more about these processes tissue cultures are frequently used experimental tools. However, apart from experiments with early kidney anlagen there is a lack of suitable in-vitro models regarding the generation and long-term maintenance of renal tubules. In the present paper we like to demonstrate an advanced culture technique, which allows to generate tubular elements derived from renal stem cells. For the growth of tubules it is essential to fine-tune the interface between the embryonic tissue and the dead fluid space within a perfusion culture container by offering a polyester artificial interstitium. Culture was performed in IMDM supplemented with hormones and growth factors but using serum-free conditions over 14 days. Formation of tissue was then analysed by immunohistochemistry and two-dimensional (2D) electrophoresis. Culture in pure IMDM leads to a complete loss of tissue formation. In contrast, application of aldosterone (A) induces the development of numerous polarised tubules. Surprisingly, addition of epidermal growth factor (EGF), a cocktail of insulin, transferrin and selenium (ITS), retinoic acid (RA), cholecalciferol (VitD 3) or bovine pituitary extract (BPT) does not further improve development of tubules, but leads to intensive cell clustering and a decrease of tubule formation. 2D Western blots of developing tissue probed with soybean agglutinin (SBA) reveal a unique pattern of newly detected proteins. It is found that growth factors do not support but abolish protein spots upregulated by aldosterone. It remains to be investigated, which cellbiological effect stimulates the embryonic cells to develop tubules in competition to cell clusters at the interphase of an artificial interstitium.

Tissue engineering: generation of differentiated artificial tissues for biomedical applications.

A new field in biomedical science has been established. Cell biologists, engineers, and surgeons now work within a team. Artificial connective, epithelial, or neuronal tissues are being constructed using living cells and different kinds of biomaterials. Numerous companies and laboratories are presenting dynamic developments in this field. Prognoses predict that, at the beginning of the coming century, the industry of tissue engineering will reach the importance of the present genetic technology. An enormous demand for organ and tissue transplants motivates research activities and drives the acquisition of innovative techniques and creative solutions. At the front of this development is the creation of artificial skin for severely burned patients and the generation of artificial cartilage for implantation in articular joint diseases. Future challenges are the construction of liver organoids and the development of an artificial kidney on the basis of cultured cells. In this paper we show strategies, needs, tools, and equipment for tissue engineering. The presupposition for all projects is the induction, development, and maintenance of differentiation within the tissue under in vitro conditions. As experiments in conventional culture dishes continued to fail, new cell and tissue culture methods had to be developed. Tissues are cultured under conditions as close as possible to their natural environment. To optimize adherence or embedding, cells are grown on novel tissue carriers and on individually selected biomatrices or scaffolds. The tissues are subsequently transferred into different types of containers for permanent perfusion with fresh culture medium. This guarantees constant nutrition of the developing tissue and prevents the accumulation of harmful metabolites. An organo-typical environment for epithelial cells, for example, is obtained in gradient containers, which are permanently superfused at the apical and basal sides with different media. Long term experiments result in cultured tissues in a quality thus far unreached.