Progress in Biomaterials最新文献

Curcumin is a primary polyphenol of the rhizomatous perennial plant called Curcuma Longa. Curcumin interferes favorably with the cellular events that take place in the inflammatory and proliferative stages of wound healing, hence its importance in skin regeneration and wound healing. Curcumin is however lipophilic, and this must be considered in the choice of its drug delivery system. Liposomes are spherical vesicles with bi-lipid layers. Liposomes can encapsulate both lipophilic and hydrophilic drugs, hence their suitability as an ideal drug delivery system for curcumin. There is, nevertheless, a tendency for liposomes to be unstable and have low encapsulation efficiency if it is not formulated properly. Formulation optimization of curcumin-loaded liposomes was studied by the application of artificial neural network (ANN) to improve encapsulation efficiency and flux of the liposomes. The input factors selected for optimization of the formulation were sonication time, hydration volume, and lipid/curcumin ratio. The response variables were encapsulation efficiency and flux. The maximum encapsulation efficiency and flux were obtained using lipid/curcumin ratio of 4.35, sonicator time of 15 min, and hydration volume of 25 mL. The maximum encapsulation efficiency and flux predicted were 100% and 51.23 µg/cm²/h, respectively. The experimental values were 99.934% and 51.229 µg/cm²/h, respectively. Curcumin-loaded liposome formulation is a promising drug delivery system in the pharmaceutical industry when formulated using optimized parameters derived from ANN statistically designed models.

Many studies have demonstrated that curcumin has potential anticancer properties. This research aims to study the effect of iron (II, III) oxide (Fe₃O₄) nanoparticles coated with carboxymethyl chitosan containing curcumin combination with hyperthermia on breast cancer cells. Magnetic nanoparticles coated with carboxymethyl chitosan containing curcumin (MNP-CMC-CUR) were prepared and specified. MCF-7, MDA-MB-231, and human fibroblast cells were treated with free curcumin and MNP-CMC-CUR at concentrations of 0-60 µM and at different time points. A combined therapy of MNP-CMC-CUR and hyperthermia was performed on MCF-7 cells. The cytotoxicity of curcumin and MNP-CMC-CUR combined with hyperthermia was assessed by MTT. The changes in TP53 and CASPASE3 gene expression were evaluated using real-time PCR. Both cell apoptosis and cell cycle were studied by Annexin/PI staining. The results of MTT showed that the IC₅₀ amount of MNP-CMC-CUR has significantly decreased compared to free curcumin (p < 0.05) and MNP-CMC-CUR in combination with the hyperthermia, and significantly reducing the metabolic activity of the cells (p < 0.05). Real-time PCR results revealed the up-regulation of TP53 and CASPASE3 (p < 0.05). The combinational therapy-induced cell apoptosis (64.51%) and sub-G1 cell cycle were arrested in MCF-7 cells. Based on these observations, a combination of MNP-CMC-CUR with hyperthermia could inhibit the proliferation of MCF-7 cells.

The need for bone tissue replacement, repair and regeneration for orthopedic application is constantly growing. Therefore, the application of cartilage substitute due to the lack of donors as well as biocompatibility leads to immune system rejection. In order to overcome these drawbacks, researchers have used porous scaffold as an option for bone transplantation. In this study, poly-lactic acid (PLA) scaffolds were prepared for cartilage application by fused deposition modeling (FDM) technique and then coated by electrospinning with polyvinyl alcohol (PVA) and hyaluronic acid (HLA) fibers. Hybrid electrospinning (ELS) method was used to produce porous scaffolds from HLA-PVA polymers. The printed scaffold was coated using FDM technique and the mechanical and biological investigation was performed on the polymeric composite specimen. The functional group and morphological behavior were investigated using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The obtained porous scaffold has hydrophilic properties as the PVA and HLA were coated on the PLA. The porous 3D-printed scaffold containing PLA/PVA/HLA scaffold does not show any toxicity in MTT evaluation after 1, 3 and 7 days. The SEM image confirmed the cell adhesion of the chondrite to the scaffold. Also, the mechanical performances of the sample, such as elastic modulus and compressive strength, were evaluated by compression test. By electro-spun coating, the elastic module of PVA/PLA and PLA/PVA/HLA scaffolds has increased to 18.31 ± 0.29 MPa and 19.25 ± 0.38 MPa. Also, the tensile strength of these two porous scaffolds has reached 6.11 ± 0.42 MPa and 6.56 ± 0.14 MPa, respectively. The failure strain of 3D printed PLA scaffold was reported to be 53 ± 0.21% and this value was reduced to 47 ± 0.62% and 42 ± 0.22% in PVA/PLA and PLA/PVA/HLA scaffolds. The cells' growth on the porous scaffolds showed a broad, spindle-shaped and regular shape. The obtained results of the chemical, physical and biological analyses showed that porous PLA/PVA/HLA scaffold has potential applications in cartilage construction.

Repaglinide, a member of the meglitinide class of drugs, is a new anti-diabetic agent that is utilized as an oral hypoglycemic agent. Using glyceryl monostearate, cetyl palmitate, and tristearin as lipids and poloxamer 188 as a surfactant, repaglinide-loaded solid lipid nanoparticles were created. Solid lipid nanoparticles were prepared utilizing an o/w microemulsion technique, which included the lipids glyceryl monostearate and tristearin, as well as waxes such as cetyl palmitate and the surfactant poloxamer 188. The mean particle size of the solid lipid nanoparticles formed was around 339 nm, with an entrapment efficiency of 82.20%. In-vitro release studies continued to be conducted using the dialysis bag diffusion technique. Within 12 h, the cumulative drug release was 88.4%. The results indicate that repaglinide was released more slowly from solid lipid nanoparticles made from tristearin and glyceryl monostearate in an equal ratio. Tristearin found the controlled release and extreme entrapment from other lipid carriers like glyceryl monostearate and cetyl palmitate. Differential scanning calorimetry demonstrates that repaglinide is entangled in amorphous or molecular state within solid lipid nanoparticles. SEM microscopy revealed that the produced repaglinide solid lipid nanoparticles had a spherical shape. After one month of storage at 2-8 °C, short-term stability testing revealed no significant alteration.

Modification of dental and orthopedic implants' surface by coating them with bioactive materials, such as hydroxyapatite (HA), diminishes the implants' fixation time. Appropriate adhesion to the substrate and stability in biological conditions are essential requirements for these coatings. In this study, sol-gel-derived HA coating was applied on the Ti-6Al-4 V substrate, which is a high-performance alloy for manufacturing bone implants. Also, titanium dioxide (TiO₂) which was prepared by the sol-gel method was used as an intermediate layer between HA coating and the substrate. The nano-scratch and potentiodynamic polarization tests were employed to evaluate the effectiveness of TiO₂ intermediate layer on improving the scratch resistance, as an indicator of coating adhesion strength, and the corrosion resistance of the coated samples. The quality of the coating bonded to the substrate was studied by cross-sectional SEM images. The XRD tests indicated that HA and TiO₂ coatings were formed with predetermined phase compositions. The biocompatibility of sol-gel-derived HA coating was established by simulated body fluid (SBF) immersion tests. The SEM images, along with the results of electrochemical and nano-scratch tests, proved the significant effect of a TiO₂ intermediate layer on improving the scratch resistance and stability of HA coating on titanium alloy substrate.

Poly(N-vinylcaprolactam) (PNVCL) is a suitable alternative for biomedical applications due to its biocompatibility, biodegradability, non-toxicity, and showing phase transition at the human body temperature range. The purpose of this study was to synthesize a high molecular weight PNVCL-PVAc thermo-responsive copolymer with broad mass distribution suitable for electrospun nanofiber fabrication. The chemical structure of the synthesized materials was detected by FTIR and ¹HNMR spectroscopies. N-Vinyl caprolactam/vinyl acetate copolymers (159,680 molecular weight (g/mol) and 2.51 PDI) were synthesized by radical polymerization. The phase transition temperature of N-vinyl caprolactam/vinyl acetate copolymer was determined by conducting a contact angle test at various temperatures (25, 26, 28, and 30 [Formula: see text]). The biocompatibility of the nanofibers was also evaluated, and both qualitative and quantitative results showed that the growth and proliferation of 929L mouse fibroblast cells increased to 80% within 48 h. These results revealed that the synthesized nanofibers were biocompatible and not cytotoxic. The results confirmed that the synthesized copolymers have good characteristics for biomedical applications.

Despite the importance of porous titanium oxide (PA-TiO₂) in diverse functional applications, very little information is available on the compatible mechanical properties for potential biomedical applications. In this study, PA-TiO₂ foam was synthesized using space-holding powder metallurgy and sintering methods to produce interconnected opened-cell structure with surface morphology of mountain-like features associated with the extensive rift valley system. Three different types of PA-TiO₂ foams with porosities of 35-52% and mean pore diameter of 190-210 μm were fabricated for evaluating the effect of porosity on mechanical properties of bulk PA-TiO₂. The modulus of elasticity of PA-TiO₂ foams exhibited in the range of 45-262 MPa which was within the range of modulus of elasticity of human cancellous bone. Cytotoxicity test is performed in vitro analysis to observe the effect of cell toxicity to produce osteointegration when used as implantable materials. There was no cytotoxicity effect found and remarkable cell growth was observed for human cancerous (HeLa) cell line. However, there was no cytotoxicity effect found and cell growth was not observed for Vero cell line. This study suggested that PA-TiO₂ facilitates cell growth without spreading toxicity and has mechanical properties of cancellous bone. Hence, it has potential application as implant and medical devices in biomedical applications.

Insufficient biological and bioactive properties of dextran hydrogels limit their applications as promising scaffolds for tissue engineering. We developed nanocomposite dextran hydrogels comprised of bioactive glass (nBGC: 64% SiO2, 31% CaO, 5% P₂O₅) nanoparticles with an average particle size of 77 nm using a chemical crosslinking of dextran chains to form 3D hydrogel networks. In the current study; bioactivity of the obtained nanocomposite hydrogels was evaluated through the formation of apatite crystal structures after the incubation in simulated body fluid (SBF) at various submersion periods and nBGC content. The scanning electron microscopy (SEM) micrographs represented an enhanced hydroxyapatite formation on the cross section of nanocomposite comprising of nBGC content from 2 to 8 (% by wt). Biomineralization results of Dex-8 (% by wt) composite during 7, 14 and 28 days immersion indicated the apatite layer formation and the growth of apatite crystal size on the surface and cross section of the nanocomposite. Moreover, MTT assessments indicated that human osteosarcoma cells (SaOS-2) were able to adhere and spread within the dextran hydrogels reinforced with the bioactive glass nanoparticles. With regard to enhanced bioactivity and biocompatibility, the developed dextran-nBGC hydrogel could be considered as a suitable candidate for bone tissue engineering application.