Mesoporous silica nanoparticles prepared by different methods for biomedical applications: Comparative study.

In the current investigation, mesoporous silica nanoparticles were obtained by various techniques, namely sol-gel (S1), micro-emulsion (S2) and hydrothermal synthesis (S3). The effect of those methods on the final features of the obtained mesoporous silica nanoparticles was studied. The obtained nanoparticles were investigated by TEM, BET surface area, Zetasizer, XRD and FTIR. The preparation method effect was evaluated on the drug release behaviour using doxycycline hyclate as a model drug. In addition, the degree of their compatibility against Saos-2 cell line was also determined. The morphology and microstructure of silica nanoparticles were found to be dependent on the utilised method. Those techniques produced particles with particle sizes of 50, 30-20 and 15 nm and also surface areas of 111.04, 164 and 538.72 m2 /g, respectively, for S1, S2 and S3. However, different preparation methods showed no remarkable changes for the physical and chemical integrities. The drug release test showed faster release from S2 compared with S1 and S3, which make them more applicable in cases require large doses for short periods. However, the release behaviour of S3 was satisfied for treatments which require long period with relatively highest release rate. The preparation method influenced the cell viability as S1 and S2 showed acceptable cell cytotoxicity compared with S3.

Nanoparticle- and Nanoporous-Membrane-Mediated Delivery of Therapeutics.

Pharmaceutical particulates and membranes possess promising prospects for delivering drugs and bioactive molecules with the potential to improve drug delivery strategies like sustained and controlled release. For example, inorganic-based nanoparticles such as silica-, titanium-, zirconia-, calcium-, and carbon-based nanomaterials with dimensions smaller than 100 nm have been extensively developed for biomedical applications. Furthermore, inorganic nanoparticles possess magnetic, optical, and electrical properties, which make them suitable for various therapeutic applications including targeting, diagnosis, and drug delivery. Their properties may also be tuned by controlling different parameters, e.g., particle size, shape, surface functionalization, and interactions among them. In a similar fashion, membranes have several functions which are useful in sensing, sorting, imaging, separating, and releasing bioactive or drug molecules. Engineered membranes have been developed for their usage in controlled drug delivery devices. The latest advancement in the technology is therefore made possible to regulate the physico-chemical properties of the membrane pores, which enables the control of drug delivery. The current review aims to highlight the role of both pharmaceutical particulates and membranes over the last fifteen years based on their preparation method, size, shape, surface functionalization, and drug delivery potential.

Novel polysaccharide hybrid scaffold loaded with hydroxyapatite: Fabrication, bioactivity, and in vivo study.

The main goal of this study was to produce a novel porous scaffold for rapid in vivo bone healing behavior. Lyophilization technique was used to produce this highly porous hybrid scaffold from Na-alginate (S) and hydroxyethylcellulose (HEC) impregnated with different concentration of hydroxyapatite (HA). After cross-linking the scaffolds, their incubation was carried out in simulated body fluid (SBF) for 4 weeks at 37 °C to investigate their bioactivity. A number of techniques were employed (e.g., XRD, FTIR, SEM, EDX, and texture analyzer) to characterize the designed scaffolds. It was observed that the mechanical properties of the scaffolds increase deformation energy (182 ±â€¯16 J/m3) and rigidity gradient (19.44 ±â€¯0.85 Pa) after loading with HA. Furthermore, the scaffolds were implanted in femur critical size defects (2 mm) of adult male Wistar rats for 6 weeks. In vitro and in vivo analyses demonstrated impressive bioactivity and biocompatibility for the prepared scaffolds, especially those containing HA. Based on the obtained results we conclude that the designed scaffolds are promising solutions for bone regeneration applications.

Novel alginate/hydroxyethyl cellulose/hydroxyapatite composite scaffold for bone regeneration: In vitro cell viability and proliferation of human mesenchymal stem cells.

Sodium alginate (SA)/hydroxyethylcellulose (HEC)/hydroxyapatite (HA) composite scaffolds were explored for enhanced in vitro bone regeneration. The SA/HEC/HA composites were synthesized using the lyophilization technique and further cross-linked in the presence of calcium ions to form composite hydrogel networks. The physicochemical, thermal behavior and morphology properties of the prepared scaffolds were characterized through XRD, DSC/TGA, FTIR and SEM. Furthermore, the mechanical behavior of the under investigated scaffolds was determined using texture analyzer. The in vitro bioactivity in SBF and adsorption of bovine serum albumin as well as cell viability for all the prepared scaffolds were also tested. The results indicated that the higher HA concentration (40wt%) enhanced the mechanical properties (23.9MPa), bioactivity and protein adsorption. Cell viability of the tested scaffolds confirmed the non-toxicity of the fabricated systems on the human mesenchymal stem cells (hMSCs). Proliferation capability was also confirmed for the tested scaffolds after 3 and 7days, but the higher HA-containing scaffold showed increased cell populations specially after 7days compared to HA-free scaffolds. This novel composite material could be used in bone tissue engineering as a scaffold material to deliver cells and biologically active molecules.