METHODS: Oligo, low, medium and high molecular weight chitosan nanoparticles were prepared by nanospray drying technique. These nanoparticles were incubated with alveolar macrophages in vitro and had model drug sodium fluorescein added into the same cell culture. The diffusion characteristics of sodium fluorescein and nanoparticle behavior were investigated using fluorescence microscopy, scanning electron microscopy, differential scanning calorimetry and Fourier transform infrared spectroscopy techniques.

RESULTS: The oligochitosan nanoparticles enabled macrophage membrane fluidization with the extent of sodium fluorescein entry into macrophages being directly governed by the nanoparticle loading. Using nanoparticles made of higher molecular weight chitosan, sodium fluorescein permeation into macrophages was delayed due to viscous chitosan diffusion barrier at membrane boundary.

MATERIALS AND METHODS: The incorporation of Tualang honey into hydroxyapatite was assessed using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and field emission scanning electron-energy dispersive X-ray analysis microscopy (FESEM-EDX). The effect of hydroxyapatite combined with Tualang honey on cell viability was determined by WST-1 assay and wound healing was assessed by scratch assay.

RESULTS: The incorporation of Tualang honey into hydroxyapatite altered the functional groups, structure, size, morphology, and components of the crystal as evidenced by FTIR, XRD and FESEM-EDX analysis. High concentrations of pamidronic acid inhibit oral fibroblast viability and wound healing. Low and high concentrations of hydroxyapatite demonstrate non-toxicity towards fibroblast cells. Furthermore, hydroxyapatite reversed the action of pamidronic acid on the cells; it increased fibroblast viability but did not close the wound. Tualang honey promotes fibroblast viability and wound closure. However, the addition of Tualang honey is unable to overcome the inhibitory effects of pamidronic acid on fibroblasts. The addition of Tualang honey and hydroxyapatite improved the cell viability and accelerated wound closure of fibroblast exposed to pamidronic acid.

Objectives: The objective of this study was to utilize a chitosan-based nanoparticle system as the delivery carrier for glutamic acid, a model for encapsulated biomolecules to visualize the in vitro release and accumulation of the encapsulated glutamic acid from chitosan nanoparticle (CNP) systems.

Methods: CNP was synthesized via ionic gelation routes utilizing tripolyphosphate (TPP) as a cross-linker. In order to track glutamic acid release, the glutamic acid was fluorescently-labeled with fluorescein isothiocyanate prior encapsulation into CNP.

Results: Light Scattering data concluded the successful formation of small-sized and mono-dispersed CNP at a specific volume ratio of chitosan to TPP. Encapsulation of glutamic acid as a model cargo into CNP led to an increase in particle size to >100 nm. The synthesized CNP exhibited spherical shape under Electron Microscopy. The formation of CNP was reflected by the reduction in free amine groups of chitosan following ionic crosslinking reactions. The encapsulation of glutamic acid was further confirmed by Fourier Transform Infrared (FTIR) analysis. Cell viability assay showed 70% cell viability at the maximum concentration of 0.5 mg/mL CS and 0.7 mg/mL TPP used, indicating the low inherent toxicity property of this system. In vitro release study using fluorescently-tagged glutamic acids demonstrated the release and accumulation of the encapsulated glutamic acids at 6 hours post treatment. A significant accumulation was observed at 24 hours and 48 hours later. Flow cytometry data demonstrated a gradual increase in intracellular fluorescence signal from 30 minutes to 48 hours post treatment with fluorescently-labeled glutamic acids encapsulated CNP.

Objectives: The aim of this study was to prepare bacterial nanocellulose/silver (BNC/Ag) nanocomposite films as ecofriendly wound dressing in order to assess their physical, cytotoxicity and antimicrobial properties. The in vitro molecular study was performed to evaluate expression of genes involved in healing of wounds after treatment with BNC/Ag biofilms.

Study design materials and methods: Silver nanoparticles were formed by using Citrullus colocynthis extract within new isolated bacterial nanocellulose (BNC) RM1. The nanocomposites were characterized using X-ray diffraction, Fourier transform infrared, and field emission scanning electron microscopy. Besides, swelling property and Ag release profile of the nanocomposites were studied. The ability of nanocomposites to promote wound healing of human dermal fibroblast cells in vitro was studied. Bioinformatics databases were used to identify genes with important healing effect. Key genes which interfered with healing were studied by quantitative real time PCR.

Results: Spherical silver nanoparticles with particle size ranging from 20 to 50 nm were synthesized and impregnated within the structure of BNC. The resulting nanocomposites showed significant antibacterial activities with inhibition zones ranging from 7±0.25 to 16.24±0.09 mm against skin pathogenic bacteria. Moreover, it was compatible with human fibroblast cells (HDF) and could promote in vitro wound healing after 48h. Based on bioinformatics databases, the genes of TGF-β1, MMP2, MMP9, CTNNB1, Wnt4, hsa-miR-29b-3p and hsa-miR-29c-3p played important role in wound healing. The nanocomposites had an effect in expression of the genes in healing. Thus, the BNC/Ag nanocomposite can be used to heal wound in a short period and simple manner.