In Situ and Ex Situ Designed Hydroxyapatite: Bacterial Cellulose Materials with Biomedical Applications

Abstract

Hydroxyapatite (HAp) and bacterial cellulose (BC) composite materials represent a promising approach for tissue engineering due to their excellent biocompatibility and bioactivity. This paper presents the synthesis and characterization of two types of materials based on HAp and BC, with antibacterial properties provided by silver nanoparticles (AgNPs). The composite materials were obtained following two routes: (1) HAp was obtained in situ directly in the BC matrix containing different amounts of AgNPs by the coprecipitation method, and (2) HAp was first obtained separately using the coprecipitation method, then combined with BC containing different amounts of AgNPs by ultrasound exposure. The obtained materials were characterized by means of XRD, SEM, and FT-IR, while their antimicrobial effect was evaluated against Gram-negative bacteria (Escherichia coli), Gram-positive bacteria (Staphylococcus aureus), and yeast (Candida albicans). The results demonstrated that the obtained composite materials were characterized by a homogenous porous structure and high water absorption capacity (more than 1000% w/w). These materials also possessed low degradation rates (<5% in simulated body fluid (SBF) at 37 °C) and considerable antimicrobial effect due to silver nanoparticles (10–70 nm) embedded in the polymer matrix. These properties could be finetuned by adjusting the content of AgNPs and the synthesis route. The samples prepared using the in situ route had a wider porosity range and better homogeneity.

Bacterial Cellulose as a Versatile Biomaterial for Wound Dressing Application

“…Therefore, they are ideal for the development of innovative specific controlled release systems, especially in biomedical engineering, including wound dressing and transdermal drug delivery systems [ 107 ]. In addition, when used as a membrane, it can contribute to an increase in cellular adhesion as well as the proliferation, migration, and differentiation of cells, thereby accelerating the re-epithelialization, which results in a faster wound healing process [ 15 , 111 ]. As previously stated, its performance as a biomaterial has attracted attention for use in drug delivery systems [ 15 , 111 , 112 , 113 ], wound dressings [ 114 ], tissue scaffolds [ 115 ], and implants [ 116 ].…”

Fabrication, Properties, and Biomedical Applications of Calcium-Containing Cellulose-Based Composites

“…It found cytocompatibility and a relatively high protein adsorption ability for cellulose/vaterite nanocomposites. Nicoara et al (2020) used the co-precipitation method and ultrasound exposure to in situ and ex situ design HA/BC/Ag composite with excellent biocompatibility, bioactivity, and antibacterial properties for tissue engineering. It carried out a homogenous porous structure and high water absorption capacity for the composites.…”

Design of Materials for Bone Tissue Scaffolds

“…Most of the studies of the Special Issue developed innovative materials favoring the formation of new bone in the fracture site where the scaffold is implanted [11][12][13][14][15][16]. Three papers investigate the issues related to the geometry/dimensions that the scaffold pores must possess to guarantee an adequate mechanobiological response [10,17,18].…”