Engineering a novel antibacterial agent with multifunction: Protocatechuic acid-grafted-quaternized chitosan.

As a mild cationic antibacterial agent, hydroxypropyltrimethyl ammonium chloride chitosan (HACC) could kill gram-positive bacteria and gram-positive drug-resistant bacteria without cytotoxicity. Nevertheless, it was not effective against gram-negative bacteria. Herein, protocatechuic acid (PA) with broad-spectrum antibacterial properties and pharmacological activities was grafted on HACC.

In vivo evaluation of the anti-infection potential of gentamicin-loaded nanotubes on titania implants.

Titanium-based implants have been widely used in orthopedic surgery; however, failures still occur. Our in vitro study has demonstrated that gentamicin-loaded, 80 nm-diameter nanotubes possessed both antibacterial and osteogenic activities. Thus, the aim of this study was to further investigate the in vivo anti-infection effect of the titanium implants with gentamicin-loaded nanotubes.

Inhibited Bacterial Adhesion and Biofilm Formation on Quaternized Chitosan-Loaded Titania Nanotubes with Various Diameters.

Titania nanotube-based local drug delivery is an attractive strategy for combating implant-associated infection. In our previous study, we demonstrated that the gentamicin-loaded nanotubes could dramatically inhibit bacterial adhesion and biofilm formation on implant surfaces. Considering the overuse of antibiotics may lead to the evolution of antibiotic-resistant bacteria, we synthesized a new quaternized chitosan derivative (hydroxypropyltrimethyl ammonium chloride chitosan, HACC) with a 27% degree of substitution (DS; referred to as 27% HACC) that had a strong antibacterial activity and simultaneously good biocompatibility with osteogenic cells.

Covalently immobilised type I collagen facilitates osteoconduction and osseointegration of titanium coated implants.

Background/objective: Plasma-sprayed titanium coating (TC) with rough surfaces has been successfully applied in hip or knee prostheses. This study aimed to investigate the osteoconduction and osseointegration of Type I collagen covalently immobilised on TC (TC-AAC) compared with those of TC.

Methods: , the migration of human mesenchymal stem cells (hMSCs) on TC and TC-AAC was observed by scanning electron microscopy and visualised fluorescent live/dead assay.

In vivo effect of quaternized chitosan-loaded polymethylmethacrylate bone cement on methicillin-resistant Staphylococcus epidermidis infection of the tibial metaphysis in a rabbit model.

Infection of open tibial fractures with contamination remains a challenge for orthopedic surgeons. Local use of antibiotic-impregnated polymethylmethacrylate (PMMA) beads and blocks is a widely used procedure to reduce the risk of infection. However, the development of antibiotic-resistant organisms make the management of infection more difficult.

Synthesis and characterization of magnetic iron oxide/calcium silicate mesoporous nanocomposites as a promising vehicle for drug delivery.

The synthesis of the mesoporous nanocomposites consisting of magnetic iron oxide nanoparticles and calcium silicate with uniform size has been a challenge, although they are the ideal potential agent for medical diagnosis and therapy. In this work, the core/shell structured mesoporous nanocomposites consisting of magnetic iron oxide nanoparticles as the core and calcium silicate as the shell have been successfully synthesized using a two liquid phase system by ultrasound irradiation, in which the hydrophobic phase is composed of hydrophobic Fe(3)O(4) nanoparticles and tetraethyl orthosilicate (TEOS), and the water phase consists of Ca(NO(3))(2), NaOH, and water. The hollow mesoporous nanocomposites consisting of magnetic iron oxide nanoparticles and calcium silicate are obtained by adding a certain amount of the inert hydrophobic solvent isooctane in the reaction system before ultrasound irradiation.