Progress in Biomaterials最新文献

Tissue engineering (TE) employs scaffolds as a structural support for initially seeding of cells followed by development of new tissues. Electrospun scaffolds generally function as a template of native extracellular matrix (ECM). The chemical composition of the scaffold and its surface morphology strongly influence the interaction between various cell types and materials. In this work, PCL and PCL/HPMC-based composite membranes with varying concentrations of HPMC (20-30% by weight) were fabricated using electrospinning technique. The membranes were evaluated for their surface, physio-chemical and biological properties. It was observed probably for the first time that blending of HPMC with PCL produced super-hydrophilic scaffolds. DSC studies confirmed the semi- crystalline nature of HPMC. PCL/HPMC composite scaffolds are found biocompatible from cytotoxicity assay. From the cell culture studies (apoptosis), PCL/HPMC composite scaffolds did not inhibit the adhesion of L929 cells due to their super-hydrophilic nature. The cell adhesion and spreading varied with HPMC concentration. PCL/HPMC (70/30) membranes showed highest cell adhesion among others due to its porous structure.

The preparation of hydrogels based on biopolymers like collagen and gum arabic gives a chance to provide novel options that can be used in biomedical field. Through a polymeric semi-interpenetration technique, collagen-based polymeric matrices can be associated with gum arabic while controlling its physicochemical and biological properties. To create novel hydrogels with their potential use in the treatment of wounds, the semi-interpenetration process, altering the concentration (0-40% by wt) of gum arabic in a collagen matrix is explored. The ability of gum arabic to create intermolecular hydrogen bonds in the collagen matrix enables the development of semi-interpenetrating polymeric networks (semi-IPN)-based hydrogels with a faster gelation time and higher crosslinking. Amorphous granular surfaces with linked porosity are present in matrices with 30% (by wt) of gum arabic, enhancing the storage modulus and thermal degradation resistance. The hydrogels swell to very high extent in hydrolytic and proteolytic environments, good hemocompatibility, and suppression of growth of pathogens like E. coli, and all it is enhanced by gum arabic included them, in addition to enabling the controlled release of ketorolac. The chemical composition of theses semi-IPN matrices have no deleterious effects on monocytes or fibroblasts, promoting their proliferation, and lowering alpha tumor necrosis factor (α-TNF) secretion in human monocytes.

Diabetes mellitus is a fast-growing chronic metabolic condition caused by insulin deficiency or resistance, leading to lifelong insulin use. It has become one of the world's most difficult non-communicable diseases. The goal of this study was to view the effectiveness of the combined method of macro- and microencapsulation for islet transplantation. The process of 3D printing is used to make macroencapsulation bags with regulated diffusion properties thanks to the emerging small pored channels. The ink used to manufacture 3D-printed bags with controlled specifications was polyurethane solution (13% w/v). Swelling experiments revealed that there was very little swelling and that the membrane maintained its structural stability. Alginate beads (made from 5% w/v solution) were used to microencapsulate islet cell clusters. Direct contact assay was used to confirm in vitro cytocompatibility. The insulin release from the encapsulated rabbit islets was confirmed using a glucose challenge assay. When challenged with 20 mM glucose on day 7, the encapsulated islet cells released insulin at a rate of 9.72 ± 0.65 mU/L, which was identical to the RIN-5F islet cell line control, confirming the functioning of the encapsulated islets. After 21 days of culture, the islets were shown to be viable utilizing a live-dead assay. As a result, our work demonstrates that 3D printing for macroencapsulating cells, as well as microencapsulation with alginates, is a viable scale-up technology with great potential in the field of pancreatic islet transplantation.

Mucoadhesive polymers improve oral bioavailability of drugs by prolonging the duration of adhesion of drugs with mucosa. Various methods could be employed to address the problems of mucoadhesive polymers like weak adhesion forces. Chemical modification of polymers, such as the addition of a thiol group or thiolation, is another way for improving the polymers' mucoadhesive properties that is studied in present research work. A novel thiomer of chitosan was prepared by attaching 2-mercaptobenzoic acid, a hydrophobic ligand onto it. The docking of thiomer and chitosan with mucin structure showed higher binding energy for former. The prepared thiomer was subjected to X-ray diffraction and DSC which established reduction in crystallinity and formation of a new compound through changes in glass transition, melting point and change in diffraction pattern. The NMR studies established conjugation of 2-mercapto benzoic acid to chitosan. The increased mucoadhesion in thiomer behaviour (2-3 fold) was confirmed through mucus glycoprotein assay as well as through texture analysis. The permeation enhancing the property of thiomer was established by demonstrating the permeation of phenol red across thiomer treated intestinal membrane. An in vitro cell toxicity assay was done to establish toxicity of chitosan and thiolated chitosan. Finally, the reduced water uptake of thiomer over chitosan proved that the increase in mucoadhesion is not contributed by swelling. Thus, a thiomer with improved mucoadhesion and enhanced permeation properties was prepared and characterized. Hence, all these properties render the newly synthesized polymer a better alternative to chitosan as an excipient for mucoadhesive drug delivery systems.

Medicinal applications of turmeric-derived curcumin have been known to mankind for long ages. Its potential in managing "cystic fibrosis" has also been evaluated. This autosomal recessive genetic disease is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) which involves an impaired secretion of chloride ions and leads to hypersecretion of thick and sticky mucus and serious complications including airway obstruction, chronic lung infection, and inflammatory reactions. This narrative review aims to highlight the available evidence for the efficacy of curcumin nanoformulations in its potential treatment of cystic fibrosis. Recent research has shown that curcumin acts on the localized mutant CFTR ion channel at the plasma membrane. Preclinical studies have also shown that curcumin nanoformulations have promising effects in the treatment of cystic fibrosis. In this context, the purpose of this narrative review is to highlight the general bioactivity of curcumin, the types of formulations and related studies, thus opening new therapeutic perspectives for CF.

The current work focuses on the formation of nanofibrous mats without the use of toxic solvents and metallic nanoparticles utilizing polyvinyl alcohol (PVA) and a blend of nigella, honey, garlic, and olive oil. Using deionized water (DI) water as a solvent, nanofibrous mats composed of PVA/nigella/honey (PNH) and PVA/garlic/honey/olive oil (PGHO) were developed. Methanol extraction was utilized to extract the therapeutic components of nigella sativa. Antibacterial and moisture management tests (MMT) were employed to examine the antibacterial and absorbance characteristics of the PNH and PGHO nanofibrous. Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) tests were employed to analyze the morphological and chemical characteristics. PGHO showed thermal stability up to 245 °C, and PNH withstands until 225 °C. PNH and PGHO both exhibited antibacterial activity against Staphylococcus aureus (S. aureus), with inhibition zones of 36 mm and 35 mm, respectively. The synthesized materials exhibited excellent absorbance properties, thermal stability, cytotoxicity, and the production of thin nanofibers with an average diameter between 150 and 170 nm. The samples were characterized using FTIR spectra, which confirmed the presence of all components in the developed samples. To date, extensive research on electrospinning for biomedical applications has been undertaken using a variety of hazardous solvents and metallic nanoparticles. Briefly, our objective is to develop nanofibrous materials from plant extracts through a process called "green electrospinning" to observe the synergistic effect of multiple biocomponents incorporated nanofibers avoiding toxic solvents and metallic compounds for potential biomedical applications.

Decellularized tissue has been used as a natural extracellular matrix (ECM) or bioactive biomaterial for tissue engineering. The present study aims to compare and analyze different decellularization protocols for mouse liver fragments and cell seeding and attachment in the created scaffold using human endometrial mesenchymal cells (hEMCs).After collecting and dissecting the mouse liver into small fragments, they were decellularized by Triton X-100 and six concentrations of sodium dodecyl sulfate (SDS; 0.025, 0.05, 0.1, 0.25, 0.5, and 1%) at different exposure times. The morphology and DNA content of decellularized tissues were studied, and the group with better morphology and lower DNA content was selected for additional assessments. Masson's tri-chrome and periodic acid Schiff staining were performed to evaluate ECM materials. Raman confocal spectroscopy analysis was used to quantify the amount of collagen type I, III and IV, glycosaminoglycans and elastin. Scanning electron microscopy and MTT assay were applied to assess the ultrastructure and porosity and cytotoxicity of decellularized scaffolds, respectively. In the final step, hEMCs were seeded on the decellularized scaffold and cultured for one week, and finally the cell attachment and homing were studied morphologically.The treated group with 0.1% SDS for 24 h showed a well preserved ECM morphology similar to native control and showing the minimum level of DNA. Raman spectroscopy results demonstrated that the amount of collagen type I and IV was not significantly changed in this group compared to the control, but a significant reduction in collagen III and elastin protein levels was seen (P < 0.001). The micrographs showed a porous ECM in decellularized sample similar to the native control with the range of 2.25 µm to 7.86 µm. After cell seeding, the infiltration and migration of cells in different areas of the scaffold were seen. In conclusion, this combined protocol for mouse liver decellularization is effective and its recellularization with hEMCs could be suitable for clinical applications in the future.

Cryogels are macroporous hydrogels that have been widely utilized in a variety of biomedical applications including wound dressings. Cryogels reveal superior mechanical and swelling properties as well as large and interconnected porosity. As traditional hydrogel wound dressings generally show undesirable mechanical and swelling characteristics, cryogels, due to their toughness and superfast swelling, offer an outstanding platform to address the growing number of various types of wounds. Moreover, recently, cryogel wound dressings loaded with an antimicrobial agent emerged as a feasible option to reduce infection, and thus improve the wound healing process. However, a comprehensive review of antimicrobial cryogels as a wound dressing is still lacking in the literature. In this review, we summarize the progress of cryogels in the area of wound dressings and provide an overview of the various polymers, namely, natural and synthetic which have been employed in cryogel wound dressing preparation. Furthermore, the most prominent antimicrobial agents incorporated in cryogel wound dressings are provided. Finally, the future directions of cryogel wound dressings for wound healing are also discussed.

Biphasic calcium phosphate (BCP) bioceramics composed of hydroxyapatite and β-tricalcium phosphate have attracted considerable attention as ideal bone substitutes for reconstructive surgery, orthopedics, and dentistry, owing to their similar chemical composition to bone mineral and biocompatibility. The addition of trace elements to BCP bioceramics, such as magnesium (Mg), cerium (Ce), and silicon (Si), can alter the physicochemical and biological properties of the resulting materials. To improve the anti-inflammatory activity of a pure BCP scaffold, this study developed a simple wet chemical precipitation and gel-casting method to fabricate microporous BCP scaffolds containing Si or Ce. The BCP scaffolds exhibited interconnected microporous structures with uniform micropores and unequiaxed grains. No changes in the phase composition and microstructure of the scaffolds with the Si or Ce doping were observed. Conversely, Si or Ce doping into the BCP crystal lattice influenced the in vitro biological activity of the scaffolds and the bone-forming ability of the cells cultured on the BCP scaffolds. The results of biological activity assays demonstrated that Ce-BCP promoted cell proliferation and osteogenic differentiation more effectively than the other scaffolds. In particular, Ce-BCP significantly suppressed the expression of bone-active cytokines via the anti-inflammatory and anti-oxidative effects. Therefore, Si- or Ce-doped BCP scaffolds can contribute to providing a new generation of bone graft substitutes.

Recent innovations in nanotechnology have opened the applicability of multifunctional nanoparticles (NPs) in biomedical diagnosis and treatment. The examples of NPs which have attracted considerable attention in recent years are metals (e.g., Au, Ag, Mg), alloys (e.g., Fe-Co, Fe-Pd, Fe-Pt, Co-Pt), iron oxides (e.g., Fe₂O₃ and Fe₃O₄), substituted ferrites (e.g., MnFe₂O₄ and CoFe₂O₄), manganites (e.g., [Formula: see text]), etc. Special attention has been paid to magnetic NPs (MNPs), as they are the potential candidates for several biomedical appliances, such as hyperthermia applications, magnetic resonance imaging, contrast imaging, and drug delivery. To achieve effective MNPs, a thorough investigation on the synthesis, and characteristic properties, including size, magnetic properties, and toxicity, is required. Furthermore, the surfaces of the NPs must be tailored to improve the biocompatibility properties and reduce agglomeration. The present review focuses on different mechanisms to develop biocompatible MNPs. The utility of these MNPs in various biomedical applications, especially in treating and diagnosing human diseases, such as targeted drug delivery, hyperthermia treatment for cancer, and other biomedical diagnoses, is thoroughly discussed in this article. Different synthetic processes and important physical properties of these MNPs and their biocomposites are presented.