Wound dressings, capable of local controlled delivery of non-steroid anti-inflammatory pain-killing drugs (NSAIDs) to the wound bed, offer great potential to accelerate wound healing, hence increase the quality of patient life. With local NSAID delivery, unwanted side effects encountered in their systemic delivery, are drastically diminished. In this study, four functional fibrous wound dressing materials, namely viscose, alginate, sodium carboxymethyl cellulose (Na-CMC) and polyethylene terephthalate (PET) loaded with a NSAID, diclofenac sodium (DCF) are prepared, and their suitability to tune the release rate of DCF is evaluated. Through careful examination of material–drug combinations, in terms of their physicochemical properties (air permeability, wettability and water retention) and structural/morphological properties (infrared spectroscopy, wide angle X-ray scattering and scanning electron microscopy), possible wound care applications are proposed. In vitro release studies using an automated Franz diffusion cell system, combined with UV-Vis absorption spectroscopy for drug release profile determination, are performed as the final pre-formulation test. Results showed significant differences in the release profiles between different material–drug combinations, making the examined materials highly applicable for several wound care applications. The present study presents a novel cost effective approach for preparation of drug loaded wound dressing materials without a sacrifice in patient safety. Additionally, novel methods and material–drug combinations are introduced, paving the way for possible future wound treatment options.
1 June 2011 in Journal of Colloid and Interface Science
The behavior of amorphous cellulose model thin films upon heat treatment is investigated. Upon heat treatment, a structural rearrangement in the films from a featureless to a fibrillar structure is observed which correlates with the regeneration time and total cellulose content as proven by atomic force microscopy and X-ray photoelectron spectroscopy. ATR-IR spectroscopy proves the presence of stronger hydrogen bonds in the heat treated surfaces which originate from a reorganization of the cellulose chains and pore structure. The rearrangement is accompanied with an increased surface hydrophobicity, a reduced swelling capacity and a reduction in the water content of the films. An increase in crystallinity of the films is not observed.
Three-dimensional scaffolds (3D) with controlled shape, dual porosity and long-term mechanical and dimensional stability in biofluids are of interest as biotemplates in tissue engineering. Herein, self-standing and lightweight cellulose-based biogenic scaffolds with a spatially structured morphology, macropores and interconnected micropores were fabricated using a combination of direct ink writing 3D printing and freeze-drying techniques. This was achieved by developing a water-based and low-cost bicomponent ink based on commercially available nanofibrillated cellulose (NFC) and carboxymethyl cellulose (CMC). Physical cross-linking through dehydrothermal treatment significantly increased the surface hardness, indentation modulus, compression strength as well as the dimensional stability of the scaffolds in biofluids, in comparison to untreated materials. However, no differences in the spectra of solid state nuclear magnetic resonance or infrared were observed for dehydrothermal treated samples, suggesting that the increase of mechanical properties and dimensional stability is based on the physical cross-linking of functional groups both at the interface between NFC and CMC. The supramolecular structure of the polymers was preserved as disclosed by X-ray diffraction measurements. The cross-linked scaffolds showed high proliferation, viability and attachment of human bone tissue derived osteoblast cells (hFOB). The simple and straightforward avenue proposed here for the design of cellulose-based fibrous inks and dual porous scaffolds from the commercially available materials and without the need of any additional crosslinkers should pave the way for the development of implantable, degradable scaffolds, and cell-laden biomaterials for bone tissue regeneration and 3D bioprinting applications.