Multi-platform arabinoxylan scaffolds as potential wound dressing materials

Biopolymers are becoming more attractive as advanced wound dressings because of their naturally derived origin, abundance, low cost and high compatibility with the wound environment. Arabinoxylan (AX) is a class of polysaccharide polymers derived from cereal grains that are primarily used in food products and cosmetic additives. Its application as a wound dressing material has yet to be realized. In this two-pronged project, arabinoxylan ferulate (AXF) was fabricated into electrospun fibers and gel foams to be evaluated as platforms for wound dressing materials. In the first study, AXF was electrospun with varying amounts of gelatin. In the second study, AXF was dissolved in water, enzymatically crosslinked and lyophilized to form gel foams. The morphology, mechanical properties, porosity, drug release kinetics, fibroblast cell response and anti-microbial properties were examined for both platforms. Carbohydrate assay was conducted to validate the presence of arabinoxylan ferulate in the electrospun GEL-AXF fibers. Swelling and endotoxin quantification studies were done to evaluate the absorptive capacity and sterilization agent efficacy respectively in AXF foams. The results indicated successful fabrication of both platforms which validated the porous, absorptive, biocompatibility and drug release properties. The results also exhibited that silver impregnated AXF scaffolds inhibited growth of Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis bacteria species, anti-microbial properties necessary to function as advanced wound dressing materials. Future work will be done to improve the stability of both platforms as well as evaluate its applications in vivo

Polysaccharide Fabrication Platforms and Biocompatibility Assessment as Candidate Wound Dressing Materials

Wound dressings are critical for wound care because they provide a physical barrier between the injury site and outside environment, preventing further damage or infection. Wound dressings also manage and even encourage the wound healing process for proper recovery. Polysaccharide biopolymers are slowly becoming popular as modern wound dressings materials because they are naturally derived, highly abundant, inexpensive, absorbent, non-toxic and non-immunogenic. Polysaccharide biopolymers have also been processed into biomimetic platforms that offer a bioactive component in wound dressings that aid the healing process. This review primarily focuses on the fabrication and biocompatibility assessment of polysaccharide materials. Specifically, fabrication platforms such as electrospun fibers and hydrogels, their fabrication considerations and popular polysaccharides such as chitosan, alginate, and hyaluronic acid among emerging options such as arabinoxylan are discussed. A survey of biocompatibility and bioactive molecule release studies, leveraging polysaccharide\u27s naturally derived properties, is highlighted in the text, while challenges and future directions for wound dressing development using emerging fabrication techniques such as 3D bioprinting are outlined in the conclusion. This paper aims to encourage further investigation and open up new, disruptive avenues for polysaccharides in wound dressing material development

An Investigation of Build Orientation on Shrinkage in Sintered Bioceramic Parts Fabricated by Vat Photopolymerization

In this work, a vat photopolymerization (VP) additive manufacturing process fabricated bioceramic cuboids at different build orientations to investigate their effects on post-sintering shrinkage and associated physical properties. A suspension of β-tricalcium phosphate (TCP) in Autodesk PR 57 commercial photopolymer resin and dimethyl sulfoxide (DMSO) solvent was used to shape green parts. Thermal treatment removed polymer from the green shape before sintering TCP at 1300 ◦C at 5 ◦C/min. Part morphology, dimensional shrinkage, and mass loss after sintering were evaluated. Part dimensions parallel to the build direction exhibited greater shrinkage compared to the other two dimensions. Mass loss was independent of build orientation. This paper is the first to investigate the relationship between build orientation and post-sintering shrinkage of bioceramic structures shaped by VP. In this work, an understanding of printing ceramic suspensions, and accounting for dimensional ceramic part shrinkage with respect to build orientation is gained to help guide print parameter selection to improve part fidelity and performance.Mechanical Engineerin

Electrospinning of PEGylated Polyamidoamine Dendrimer Fibers

Polyamidoamine (PAMAM) dendrimers have emerged as an important class of nanostructured materials and have found a broad range of applications. There is also an ongoing effort to synthesize higher-complexity structures using PAMAM dendrimers as enabling building blocks. Herein, we report for the first time the fabrication of electrospun nanocomposite fibers composed of dendrimer derivatives, namely PEGylated PAMAM dendrimers, blended with a small amount of high-molecular-weight polyethylene oxide (PEO). Morphological features and mechanical properties of the resulting dendrimer fiber mats were assessed

Semi-Interpenetrating Network (SIPN) Gelatin Nanofiber Scaffolds for Oral Mucosal Drug Delivery

The oral mucosa is a promising absorption site for drug administration because it is permeable, highly vascularized and allows for ease of administration. Nanofiber scaffolds for local or systemic drug delivery through the oral mucosa, however, have not been fully explored. In this work, we fabricated electrospun gelatin nanofiber scaffolds for oral mucosal drug delivery. To improve structural stability of the electrospun gelatin scaffolds and allow non-invasive incorporation of therapeutics into the scaffold, we employed photo-reactive polyethylene glycol diacrylate (PEG-DA575, 575 gmol-1) as a cross-linker to stabilize the scaffold by forming semi-interpenetrating network gelatin nanofiber scaffolds (sIPN NSs), during which cross-linker concentration was varied (1x, 2x, 4x and 8x). The results showed that electrospun gelatin nanofiber scaffolds after being cross-linked with PEG-DA575 (i.e. sIPN NS1x, 2x, 4x and 8x) retained fiber morphology and possessed improved structural stability. A series of structural parameters and properties of the cross-linked electrospun gelatin scaffolds were systematically characterized in terms of morphology, fiber diameter, mechanical properties, porosity, swelling and degradation. Mucin absorption onto sIPN NS4x was also confirmed, indicating this scaffold possessed greatest mucoadhesion properties among those tested. Slow release of nystatin, an anti-fungal reagent, from the sIPN gelatin nanofiber scaffold was demonstrated

Electrospun Gelatin-arabinoxylan Ferulate Composite Fibers for Diabetic Chronic Wound Dressing Application

Blends of arabinoxylan ferulate (AXF) and gelatin (GEL) at 1:1, 2:1 and 4:1 mass ratios were electrospun into composite fibrous mats as a wound-healing drug delivery platform. The composite fibers were characterized in terms of morphology, tensile properties, pore size, porosity and molecular composition. The composite fibers showed excellent cytocompatibility. Silver was impregnated into GEL-AXF nanofibers, and it was slowly released, resulting in bacterial growth inhibition as confirmed by the Kirby—Bauer disk-diffusion assay. This work establishes an electrospun arabinoxylan fibrous material platform with the potential to treat chronic diabetic wounds

Fabrication, Characterization, and in Vitro Evaluation of Silver-Containing Arabinoxylan Foams as Antimicrobial Wound Dressing

Arabinoxylan ferulate (AXF) foams were fabricated via enzymatic peroxidase/hydrogen peroxide crosslinking reaction followed by freeze-drying and studied as a potential wound dressing material. The AXF foam\u27s rheological, morphological, porous, and swelling properties were examined. AXF foams were found to be a viscoelastic material that proved to be highly porous and water absorbent. AXF foams possessed low endotoxin levels and were cytocompatible with fibroblasts. Silver was successfully integrated into AXF foams and slowly released over 48 h. AXF foams impregnated with silver demonstrated efficacy inhibiting bacterial growth according to a modified Kirby-Bauer disk diffusion susceptibility test. Overall, AXF foams possess appropriate material properties and the silver-loaded AXF foams showed antimicrobial activity necessary to be a candidate material in wound dressing development