Nicotinamide Riboside, a Promising Vitamin B3 Derivative for Healthy Aging and Longevity: Current Research and Perspectives.

Many studies have suggested that the oxidized form of nicotinamide adenine dinucleotide (NAD+) is involved in an extensive spectrum of human pathologies, including neurodegenerative disorders, cardiomyopathy, obesity, and diabetes. Further, healthy aging and longevity appear to be closely related to NAD+ and its related metabolites, including nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN). As a dietary supplement, NR appears to be well tolerated, having better pharmacodynamics and greater potency. Unfortunately, NR is a reactive molecule, often unstable during its manufacturing, transport, and storage. Recently, work related to prebiotic chemistry discovered that NR borate is considerably more stable than NR itself. However, immediately upon consumption, the borate dissociates from the NR borate and is lost in the body through dilution and binding to other species, notably carbohydrates such as fructose and glucose. The NR left behind is expected to behave pharmacologically in ways identical to NR itself. This review provides a comprehensive summary (through Q1 of 2023) of the literature that makes the case for the consumption of NR as a dietary supplement. It then summarizes the challenges of delivering quality NR to consumers using standard synthesis, manufacture, shipping, and storage approaches. It concludes by outlining the advantages of NR borate in these processes.

Comparative Analysis of Osteointegration in Hydroxyapatite and Hydroxyapatite-Titanium Implants: An In Vivo Rabbit Model Study.

The study evaluates the osteointegration of hydroxyapatite (HAp) and hydroxyapatite-titanium (HApTi) biocomposites implanted in the femurs of rabbits. The biocomposites were fabricated using powder metallurgy and subjected to a two-step sintering process. Scanning electron microscopy (SEM) was employed to analyze the morphology, while mesenchymal stem cells were cultured to assess cytotoxicity and proliferation. In vivo experiments involved the implantation of HAp in the left femur and HApTi in the right femur of twenty New Zealand white rabbits. Computed tomography (CT) scans, histological, immunohistochemical, and histomorphometric analyses were performed to assess bone density and osteoblast activity. Results demonstrated that HApTi implants showed superior osteointegration, with higher peri-implant bone density and increased osteoblast count compared to HAp implants. This study concluded that HApTi biocomposites have potential for enhanced bone healing and stability in orthopedic applications.

Enhanced Antibacterial Efficacy of Bioceramic Implants Functionalized with Ciprofloxacin: An In Silico and In Vitro Study.

This study explores the antibacterial efficacy and cytotoxicity of ciprofloxacin-functionalized bioceramic implants. We synthesized hydroxyapatite-ciprofloxacin (HACPXCS) composites and applied them to titanium substrates (Ti-HA-CPX), evaluating their performance in vitro against Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922). Antibacterial activity was assessed using the Kirby-Bauer disc diffusion method, while cytotoxicity was tested using mesenchymal stem cells. The results demonstrated that Ti-HA-CPX exhibited superior antibacterial activity, with inhibition zones of 33.5 mm (MIC 0.5 µg/mL) for Staphylococcus aureus (ATCC 25923) and 27.5 mm (MIC 0.25 µg/mL) for Escherichia coli (ATCC 25922). However, Ti-HA-CPX showed moderate cytotoxicity (80% cell viability). HACPXCS composites, whether chemically synthesized or mechanically mixed (HACPXMM), also displayed significant antibacterial activity, but with cytotoxicity ranging from low to moderate levels. Molecular docking studies confirmed strong binding affinities between ciprofloxacin and bacterial proteins, correlating with enhanced antibacterial efficacy. These findings suggest that Ti-HA-CPX composites offer a promising approach for single-stage surgical interventions in treating chronic osteomyelitis and infected fractures, balancing antibacterial effectiveness with manageable cytotoxicity.

Hydroxyapatite-ciprofloxacin delivery system: Synthesis, characterisation and antibacterial activity.

The main objective of this study was to synthesize hydroxyapatite-ciprofloxacin composites using a chemical precipitation method and to evaluate the properties and in vitro release profile of the drug from the hydroxyapatite-ciprofloxacin composites. Composite characterization was achieved by FT-IR, XRD and DLS. Ciprofloxacin determination was accomplished by HPLC, resulting in good incorporation efficiency of the drug (18.13 %). The in vitro release study (Higuchi model C = K t1/2 and Ritger-Peppas model, C = K t0.6) showed a diffusion-controlled mechanism. The antibacterial activity showed that the bacterial growth inhibition zones were approximately equal for the synthesis composites and for the mechanical mixture on the Staphylococcus aureus germ. The use of hydroxyapatite, which is a biocompatible, bioactive and osteoconductive material, with ciprofloxacin, which has good antibacterial activity in this composite, makes it suitable for the development of bone grafts. Furthermore, the synthesis process allows a slow local release of the drug.