Dharman Govindaraj

Osteoblast compatibility of minerals substituted hydroxyapatite reinforced poly(sorbitol sebacate adipate) nanocomposites for bone tissue application

The main focus of this investigation is to explore minerals (M) substituted hydroxyapatite (M-HAP) as reinforcing agents to strengthen poly(sorbitol sebacate adipate) (PSSA), a biodegradable polymer for soft and hard tissue applications while not considerably compromising their biocompatibility. PSSA strengthened with different weight percentage of M-HAP nanocomposite was synthesized using a microwave irradiation technique. The functional groups within the nanocomposites were determined by Fourier transform infrared (FT-IR) spectroscopic and X-ray diffraction (XRD) analysis. X-ray photoelectron spectroscopy (XPS) further showed the interface interaction between the M-HAP and PSSA. The morphological and elemental analysis was obtained from field emission-scanning microscopy (FE-SEM) equipped with energy-dispersive X-ray (EDX) spectroscopic analysis and transmission electron microscopy (TEM). The addition of M-HAP greatly increased the mechanical, thermal properties and improved the protein adsorption ability. In vitro bioactivity in simulated body fluid (SBF) experiment and human osteosarcoma MG63 (HOS MG63) cells proliferated on the M-HAP/PSSA shows that the nanocomposite has sensible cell biocompatibility. All these observations suggest that the M-HAP/PSSA nanocomposites will be promising biomaterials for bone tissue engineering applications.

Mineral substituted hydroxyapatite coatings deposited on nanoporous TiO2 modulate the directional growth and activity of osteoblastic cells

The biocompatibility of anodized titanium (TiO2) was improved by electrophoretically deposited mineral (strontium (Sr), magnesium (Mg) and zinc (Zn)) substituted hydroxyapatite (M-HAP). The M-HAP layer was grown on the anodized Ti surface at different deposition temperatures (room temperature, 60 and 80 °C). The phases and morphologies of the M-HAP layers were influenced by the deposition temperature. The coatings were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy equipped with energy dispersive X-ray analysis (SEM-EDX). Also, the effects of temperature and the mineral substitution of Sr, Mg and Zn for Ca on the physiochemical and biological properties of the M-HAP coatings were evaluated by the mechanical strength, ion dissolution and proliferation, alkaline phosphatase (ALP) activity and osteogenic expression of osteoblast like cells MG66 (HOS). Thus, the M-HAP deposition of TiO2 will serve as a potential candidate for orthopedic applications.

From waste to high-value product: Jackfruit peel derived pectin/apatite bionanocomposites for bone healing applications

Public requirements encouraged by the current asset framework drive industry to expand its general effectiveness by enhancing existing procedures or finding new uses for waste. Thus, the aim of this study was the isolation, fabrication, and characterization of pectin derived from jackfruit (Artocarpus heterophyllus) peels and the generation of hybrid of pectin (P)/apatite (HA) (P/HA) bionanocomposites. In this process, the natural pectin polymer derived from the peel of jackfruits was used in different concentrations for the fabrication of HA bionanocomposites. Characterization of the isolated pectin and bionanocomposites samples was performed with 1H NMR and 13C NMR, FTIR, XRD, SEM-EDX, and HR-TEM. Cytocompatibility, ALP, fibroblast stem cells, anti-inflammatory and cell adhesion testing of the fabricated bionanocomposites was showed good biocompatibility. Our results signify that the fabricated bionanocomposites might be applicable as bone graft materials.

Assembling of multifunctional latex-based hybrid nanocarriers from Calotropis gigantea for sustained (doxorubicin) DOX releases

Natural rubber Latex (Lax) is a colloidal dispersion of polymer particles in liquid and shows good biodegradable, biocompatibility, and non-toxicity. Natural polymers are the most important materials used in food packaging, micro/nano-drug delivery, tissue engineering, agriculture, and coating. In the present study, natural compounds extracted from plant Lax were designed to function as drug carriers using various surfactants via emulation and solvent evaporation method. Calotropis gigantea belongs to the family Apocynaceae and has received considerable attention in modern medicine, ayurvedeic, siddha, and traditional medicine. Since, we were isolated biodegradable, non-toxic, and biocompatible materials as latex from Calotropis gigantea plant. The Lax was separated as per their solubility nature and it was designed as a carrier using surfactant namely; Sorbitanmonolaurate (Span-20), sodium lauryl sulfate (SLS), and cetyltrimethylammonium bromide (CTAB). The isolated compounds from Lax of Calotropis gigantea were analyzed using high-performance liquid chromatography. To confirm the encapsulation efficiency and in vitro drug release of the carriers, doxorubicin (DOX) was used as a model natural drug. The hybrid nanocarriers were successfully synthesized through simple solvent evaporation using three surfactants, and the morphology was characterized by SEM and TEM technique. The functionality and crystalline nature of the nanocarriers were confirmed using FTIR and XRD, respectively. Within 90min, the maximum amount of DOX was encapsulated in the carriers, and prolonged cumulative drug release by the nanocarriers was observed. The formulated natural carriers were found to have potentially effective cytotoxic effects on lung cancer cells.

Mineral-substituted hydroxyapatite reinforced poly(raffinose-citric acid)–polyethylene glycol nanocomposite enhances osteogenic differentiation and induces ectopic bone formation

In this study, mineral-substituted hydroxyapatite (M-HA (5, 10, and 15 wt%)) reinforced poly(raffinose-citric acid)–polyethylene glycol–poly(raffinose-citric acid) (PRC–PEG–PRC) was synthesized employing a microwave irradiation technique. The ability of the fabricated nanocomposite for bone development was studied in vitro using human osteosarcoma HOS MG63 cells and in vivo after subcutaneous implantation into Wistar rats. This porous M-HA/PRC–PEG–PRC nanocomposite encouraged the adhesion, growth, and multiplication of HOS cells, as displayed by their uniform morphology and as determined by cell adhesion and the live/dead cell assay. Upon osteogenic differentiation, superior ALP activity and bone-related gene expression were observed for the HOS cells on the M-HA/PRC–PEG–PRC nanocomposite compared with the cells on pure PRC–PEG–PRC scaffolds. In in vivo implantation experiments, ossification and development of trabeculae were detected on the M-HA (15 wt%)/PRC–PEG–PRC nanocomposite in contrast to pure PRC–PEG–PRC. In addition, the porous M-HA (15 wt%)/PRC–PEG–PRC nanocomposite demonstrated the capacity for ectopic bone arrangement. Moreover, decreased numbers of bacterial colonies of Staphylococcus aureus and Escherichia coli were observed in the presence of the M-HA/PRC–PEG–PRC scaffolds, indicating the reduced risk for implant failure after implantation. The good cell affinity of the M-HA/PRC–PEG–PRC porous materials indicated that they might be used as scaffolds for bone tissue engineering.

The synthesis, characterization and in vivo study of mineral substituted hydroxyapatite for prospective bone tissue rejuvenation applications

Minerals substituted apatite (M-HA) nanoparticles were prepared by the precipitation of minerals and phosphate reactants in choline chloride-Thiourea (ChCl-TU) deep eutectic solvent (DESs) as a facile and green way approach. After preparation of nanoparticles (F-M-HA (F=Fresh solvent)), the DESs was recovered productively and reprocess for the preparation of R-M-HA nanoparticles (R=Recycle solvent).The functional groups, phase, surface texture and the elemental composition of the M-HA nanoparticles were evaluated by advance characterization methods. The physicochemical results of the current work authoritative the successful uses of the novel (ChCl-TU) DESs as eco-friendly recuperate and give the medium for the preparation of M-HA nanoparticles. Moreover, the as-synthesized both M-HA nanoparticles exhibit excellent biocompatibility, consisting of cell co-cultivation and cell adhesion, in vivo according to surgical implantation of Wistar rats.

Binary functional porous multi mineral–substituted apatite nanoparticles for reducing osteosarcoma colonization and enhancing osteoblast cell proliferation

We investigated the use of combined nanoparticles in bone replacement for patients with bone cancer. Bismuth (Bi) is known to have antitumor effects, and the inclusion of Bi in bioactive mineral (M)-substituted hydroxyapatite (M-HAP) may provide anti-cancer properties implant resources. A series of Bi-substituted M-HAP (Bi-M-HAP) nanoparticles with various Bi concentrations was synthesized via the ultrasound irradiation method. The nanoparticles were examined using physicochemical strategies. The cell-substance interface of the nanoparticles was observed in vitro with human osteosarcoma cells and cell multiplication was measured at 1, 3, and 7days of incubation and in vivo in rats after 3weeks of implantation. The nanoparticles promoted osseous proliferation, improved mechanical strength, and repressed the development of cancerous cells. Overall, Bi-M-HAP nanoparticles show promise for treatment of bone cancer and advance the field of embedded biomaterials.

Fabrication of Bilayer Coating of Poly(3,4-ethylenedioxythiophene)-Halloysite/Chitosan and Mg2+/Sr2+-Doped HAP on Titanium Alloy for Biomedical Implant Applications: Physicochemical and In Vitro Biological Performances Studies

The prime objective of the present work is to develop biocompatible overlayer-deposited titanium alloys to replace already available titanium alloy-based biomaterials for implantation applications. Here, we prefer to use a bilayer coating on titanium alloys instead of single coating. The adhesion and biocompatibility of titanium alloy is improved by coating with a bilayer, for example, PEDOT-HNT/CS-MHA composite using the electrochemical deposition method. Corrosion behavior of the PEDOT-HNT/CS-MHA bilayer composite coating was investigated in the PBS medium by polarization studies. The functional groups, phase purity, surface morphology, and wettability of the PEDOT-HNT/CS-MHA were characterized by various instrumental techniques like FTIR, XRD, SEM, and contact angle techniques. From the above studies, it is proved that PEDOT-HNT/CS-MHA-coated Ti alloy showing a better biocompatibility and corrosion resistance than the PEDOT-HNT-deposited Ti alloy. In addition, the in vitro bactericidal and cell viability studies were also carried out to further confirm the biocompatibility of the protective coating. Hence, the bilayer deposition has shown excellent stability and biocompatibility and can be used for the potential biomaterials for orthopedics applications.