Tetracycline hydrochloride (TCH)-loaded drug carrier based on PLA:PCL nanofibre mats: experimental characterisation and release kinetics modelling

The experimental characterisation of electrospun poly(lactic acid) (PLA): poly(e-caprolactone) (PCL) as drug carriers, at five blend ratios from 1:0, 3:1, 1:1, 1:3 and 0:1, was holistically investigated in terms of their morphological structures, crystallinity levels and thermal properties. A widely used antibiotic tetracycline hydrochloride (TCH) was loaded to prepared fibrous mats at TCH concentrations of 1 and 5 wt%. The additional TCH into PLA: PCL better facilitates the reduction of fibre diameter than polymer blends. Increasing the TCH concentration from 1 to 5 wt% was found to result in only a modest decrease in the crystallinity level, but a significant increase in the crystallisation temperature (Tc) for PLA within PLA: PCL blends. The infrared spectra of fibre mats confirm the successful TCH encapsulation into fibrous networks. The first order and Zeng models for drug release kinetics were in better agreement with experimental release data, indicating the release acceleration of TCH with increasing its concentration. In a typical case of PLA: PCL (1:1) loaded with 5 wt% TCH, the fibre mats apparently demonstrate more wrinkled and floppy structures and increased fibre diameters and decreased inter-fibrous spaces after 7-day in vitro fibre degradation, as opposed to those obtained after 3-h degradation

In vitro and in vivo bacterial antifouling properties of phosphite plasma-Treated silicone

In order to improve their bacterial antifouling property, silicone surfaces were functionalized through the plasma polymerization (PP) technique using diethyl phosphite as the precursor. The functionalized surfaces were characterized using contact angle measurements, contact angle titration, Fourier transform infrared-Attenuated total reflection spectroscopy and in vitro cytotoxicity assay. The amount of non-specific protein adsorption and the conformational changes of surface-Adsorbed proteins were investigated. Antifouling properties of the surfaces were evaluated in vitro and in vivo. PP functionalization generated a hydrophilic and amphoteric surface with a very good protein and bacterial antifouling property and caused less conformational changes on the secondary structure of surface-Adsorbed proteins. In in vivo conditions, no slime layer was formed around bacteria that adhered on the PP-functionalized surface. It is concluded that the amphoteric nature of the PP-functionalized surface is the reason for the good antifouling property. © 2019 ICE Publishing: All rights reserved

Cell interactions with superhydrophilic and superhydrophobic surfaces

Interactions of cells with biomaterials dictate their biocompatibility and biofunctionality, and are strongly influenced by surface properties. Moreover, it is important to control cell adhesion to surfaces for biological studies and diagnosis. Surface properties influence protein adsorption in terms of conformation and quantity adsorbed that further affects cell adhesion and proliferation. Several works have demonstrated that wettability influences cell attachment and proliferation. However, most studies have reported the influence of the surface energy of smooth substrates within a limited range of wettabilities. By controlling the roughness and the hydrophilicity of the surface, one can obtain biomimetic substrates with a wettability ranging from superhydrophobic to superhydrophilic. This review intends to summarize recent works, where the interaction of cells with surfaces with extreme wettabilities was investigated. Such information may be relevant in different biomedical and biological applications including diagnosis, cell biology, or tissue engineering