PROGRESS IN BIOMATERIALS
Year:2019 | Volume:8 | Issue:1|Papers Count:6

Hydroxyapatite was obtained by bone calcinations. To study the calcination process, bovine and porcine bones were first autoclaved to remove fat and other non-bone tissues. They were then heated in an alumina pan in an oxidizing atmosphere of air, where simultaneous thermal analysis curves were recorded. To prepare the hydroxyapatites, bone samples were calcined at 850 ° C and 1000 ° C using a muffle furnace for 1 h. The obtained materials were powdered using mortar and pestle, and sifted in a sieve (60 mesh) without any additional purification or chemical treatment. The materials obtained were characterized by energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The antimicrobial properties of these materials were determined through direct contact tests against Staphylococcus aureus. The natural hydroxyapatites obtained by bone calcination inhibited S. aureus growth, with the material obtained by calcination of bovine bones at 1000 ° C, showing the best antimicrobial activity. These results indicated that bone wastes can be used to obtain hydroxyapatites with antimicrobial activity.

Metal nanoparticles are widely used for the delivery and targeting of pharmaceutical, therapeutic and diagnostic agents in cancer therapy in recent years. The multifunctional nanoparticles constructed currently are supposed to show superior effects on cancer cells. This study was conducted to observe the difference between the effect of a biologically important peptide, silver (AgNPs) and gold (AuNPs) nanoparticles and their conjugates on two different cancer cells. Peptide (Boc-L-DP-LOMe) was acquired from different sources and subjected to conjugation with biosynthesized gold and silver nanoparticles under standard conditions. These conjugates were tested against the colon cancer (HT-29) and breast cancer (MDA MB-231) cell lines. The results clearly depicted the improved activity of nanoparticles in the form of conjugates. Fluorescent dye microscopy and DNA fragmentation assay substantiate the fact that the conjugated nanoparticles cause higher level of disintegration of DNA in cells that consecutively damages and causes apoptosis due to lethality.

In vitro effect of 1% theobromine addition on the physical and chemical properties of conventional glass ionomer (GIC) cement was investigated. Conventional GIC (GIC-C) and 1% theobromine added to GIC (GIC-THEO) specimens were compared regarding the microhardness (n = 10), sorption (n = 5), solubility (n = 5), color change (n = 10), fluoride release in saliva (n = 10) and the amount of biofilm deposition (n = 20). Compared against conventional GIC, adding 1% theobromine increased microhardness (p < 0. 05), while its sorption, solubility, color and fluoride release to saliva (p > 0. 05) remained unchanged. On the other hand, Streptococcus mutans biofilm amount deposited on its surface decreased statistically when theobromine was added to GIC (p < 0. 05). Based on the results, it could be concluded that 1% theobromine addition to GIC can be a good strategy as it keeps some of its properties and improves microhardness and biofilm deposits strengthening its role in the preventive approach of dentistry.

A hybrid hydrogel was obtained from decellularized extract from Wharton’ s jelly (DEWJ) and silk fibroin (SF) and characterized for cartilage tissue engineering. Wharton’ s jelly was used due to its similarity with articular cartilage in extracellular matrix composition. Also, silk fibroin has good mechanical properties which make this construct appropriate for cartilage repair. Decellularization of Wharton’ s jelly was verified by DAPI staining, DNA quantification, and PCR analysis. Then, the biochemical composition of DEWJ was determined by ELISA kits for total proteins, collagens, sulfated glycosaminoglycans (sGAG), and transforming growth factor β 1 (TGF-β 1). After fabricating pure SF and SF/DEWJ hybrid hydrogels, their physical and mechanical properties were characterized by FESEM, Fourier-transform infrared spectroscopy (FTIR) and rheological assays (amplitude and frequency sweeps). Furthermore, cell viability and proliferation were assessed by MTT assay. The results have shown that DEWJ in hybrid hydrogels enhances mechanical properties of the construct relative to pure SF hydrogels. Also, this extract at its 40% concentration in culture media and 20% or 40% concentrations in SF/DEWJ hybrid hydrogels significantly increases population of the cells compared to control and pure SF hydrogel after 7 days. In conclusion, this study proposes the potential of SF/DEWJ hybrid hydrogels for cartilage tissue engineering applications.

Candida albicans (C. albicans) belongs to the opportunistic fungal pathogens, which cause a wide spectrum of infections in immune-compromised patients. Graphene oxide (GO), a biocompatibility agent, has been reported to exhibit effective antimicrobial activity. In the present study, a graphene oxide/fluconazole (GO/Flu) compound was synthesized and characterized using Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The antifungal activity of GO/Flu was examined against fluconazole-resistant C. albicans (ATCC 10231) compared to GO and Flu using the broth microdilution method, according to CLSI protocol. DNA fragmentation was assessed through the antifungal mechanism of GO/Flu. The release of Fluin PBS medium was measured. Moreover, the cytotoxicity effect of GO/Flu on SW480 cell line was evaluated. Indeed, adhesion ability of C. albicans-treated GO/Flu against SW480 cell line was assessed. The minimum inhibitory concentration (MIC) of GO, Flu, and GO/Flu was determined at 800 μ g/mL, 16 μ g/mL, and 400– 9 μ g/mL, respectively. Notably, GO/Flu exhibited an intense antifungal activity compared to GO and Flu. In addition, GO/Flu showed much less cell toxicity against SW480 cell line than GO and Flu (P < 0. 05). The release determination of Flu in PBS (pH 7. 4) medium was 72. 42%. GO/Flu reduced the adhesion ability of C. albicans to SW480 cell line significantly. DNA fragmentation assay indicated that GO/Flu potentially degraded the DNA of C. albicans and caused a fungicidal influence. According to the findings, GO/Flu could enhance the antifungal activity against C. albicans through DNA fragmentation with low cytotoxicity effect.

The present communication warrants the presence of significant wound healing bio-efficacy of aq. alc. extract of the seed (49. 78%) of the plant Madhuca longifolia. A family of seven flavonoid fractions have been ascertained in the seed aq. alc. extract of the target plant using LCMS-8030 analysis. In vivo wound healing parameters (wound area, wound closure, epithelization period, skin breaking strength and hydroxyproline content) have been examined in Swiss albino mice models. Statistically significant (p < 0. 001) enhancement in the wound healing bio-efficacy has been effectively induced using flavonoid-loaded gold: ( Mlf@AuNps), silver: ( Mlf@AgNps), and Au– Ag bimetallic: ( Mlf@Au– AgNps) nanoparticles. Among the biofabricated nano-biomaterials, Mlf@ AgNps exhibited an exceptional enhancement in the wound healing bio-efficacy (80. 33%) attaining almost to the level of reference drug Placentrex (84. 02%). All the fabricated nano-biomaterials were thoroughly characterized using UV– Vis, XRD, FE-SEM, TEM, EDX, and DLS. The promising enhancement in the wound healing potential of the nano-biomaterial ( Mlf@AgNps) has been explained based on the cumulative effects of biological and nanotech parameters. The bio-fabricated ( Mlf@AgNps) nano-biomaterials using the plant M. longifolia have lustrous prospects for the development of complimentary herbal nanomedicine for scaling-up the wound healing bio-efficacy.