Biomimetic and biodegradable cellulose acetate scaffolds loaded with dexamethasone for bone implants

Abstract

There is, as a matter of fact, an ever increasing number of patients requiring total hip replacement (Pabinger, C.; Geissler, A. Osteoarthritis Cartilage 2014, 22, 734–741). Implant-associated acute inflammations after an invasive orthopedic surgery are one of the major causes of implant failure. In addition, there are instability, aseptic loosening, infection, metallosis and fracture (Melvin, J. S.; Karthikeyan, T.; Cope, R.; Fehring, T. K. J. Arthroplasty 2014, 29, 1285–1288). In this work, a drug-delivery nanoplatform system consisting of polymeric celluloce acetate (CA) scaffolds loaded with dexamethasone was fabricated through electrospinning. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) indicated the successful fabrication of these structures. Cytotoxicity studies were performed by using MTT assay, methylene-blue staining and SEM fixation and showed very good cell adhesion and proliferation, indicating the cytocompatibility of these fibrous scaffolds. Drug-release kinetics was measured for the evaluation of a controllable and sustained release of anti-inflammatory drug onto the engineered implants and degradation study was conducted in order to assess the mass loss of polymers. This drug-delivery nanoplatform as coating on titanium implants may be a promising approach not only to alleviate but also to prevent implant-associated acute inflammations along with a simultaneous controlled release of the drug.

Drug Eluting Bioresorbable Cellulose Acetate/PEO/HPMC Composite With Propolis Extracts for Suturing Application

“…The samples were then taken out at specific time intervals, dried at 40°C and weighed. The degree of degradation was calculated with the help of the following equation where W0 is the initial weight of the sample and W1 is the final weight of the sample [36]: Cellulose acetate is a semi-synthetic polymer where the cellulose is partially esterified with acetic acid rendering it hydrophobic. Besides having surface hydrophobicity, the polymer is also found to be susceptible to degradation in aqueous solutions due to the presence of esters.Due to the presence of ester groups in the cellulose acetate structure it most easily gets attacked by H2O molecules by hydrolysis reaction thereby the degradation starts.…”

“…Especially with absorbable sutures there is a high risk of infection due to prolonged contact of the foreign material with the tissues. Drug eluting suture materials can be used in order to surgery infections [36]. Normally in braided sutures the infection rate is high.…”

Carbohydrate‐based nanomaterials for biomedical applications

“…Chlorohexidine‐containing CA electrospun nanofibers showed antibacterial activity against oral pathogens, permitting a release of the drug over 90 days (De Carvalho et al, ). Dexamethasone‐loaded electrospun CA scaffolds provided a good environment for cell growing and proliferation, suggesting the possibility to reduce implant‐associated acute inflammations and impede implant failure (Tsiapla et al, ). Functionalized stimuli‐responsive CA were also developed.…”

Polysaccharide-Based Systems for Targeted Stem Cell Differentiation and Bone Regeneration

“…Results show a degradation of less than 25% in 150 days and no adverse effects on L929 fibroblasts. The scaffolds exhibit a biphasic release behavior into PBS, with an initial burst release of less than 20% and prolonged release over 180 days [92]. Pullulan and human-like collagen were cross-linked with diepoxyoctane, washed, cast into hydrogels, and subsequently freeze-dried.…”