Pharmacological comparison of four biopolymeric natural gums as hemostatic agents for management of bleeding wounds: preliminary in vitro and in vivo results

A review on tragacanth gum: A promising natural polysaccharide in drug delivery and cell therapy

Tragacanth is an abundant natural gum extracted from wounds created in some plants and is dried for use in various applications from industry to biomedicines. It is a cost-effective and easily accessible polysaccharide with desirable biocompatibility and biodegradability, drawing much attention for use in new biomedical applications such as wound healing and tissue engineering. Moreover, this anionic polysaccharide with a highly branched structure has been used as an emulsifier and thickening agent in pharmaceutical applications. In the following, this gum has been interested as an appealing biomaterial for producing engineering tools in drug delivery. Furthermore, the biological properties of tragacanth gum have made it a favorable biomaterial in cell therapies, especially for bone tissue engineering. This review aims to discuss the recent studies on this natural gum as a potential carrier for different drugs and cells.

Fabrication, characterization and efficacy evaluation of natural gum-based bioactive haemostatic gauzes with antibacterial properties

Management of uncontrolled bleeding due to traumatic injuries occurring in battlefields and road traffic accidents is a major healthcare concern, especially in developing countries like India. Since natural coagulation mechanism alone is insufficient to achieve haemostasis quickly in such cases, application of an external haemostatic product is generally required to accelerate the coagulation process. We had recently reported preliminary comparison of four natural absorbent gums, which indicated towards haemostatic potential of gum tragacanth (GT) and xanthan gum (XG). Present study involves fabrication of haemostatic dressings incorporated with different concentrations of GT or XG, along with ciprofloxacin (a broad-spectrum antibiotic) and other excipients over woven cotton gauze. Prepared gauzes were investigated for physico-chemical characteristics, in-vitro blood interaction studies, antibacterial effect and in-vivo haemostatic efficacy in Sprague Dawley rats using two bleeding models. Acute dermal toxicity studies were also carried out as per OECD guidelines. SEM studies showed that gauzes coated with XG had thin, uniform layer of coating, while in case of GT; coating was comparatively rough with insoluble particles of GT adhering over gauze surface, forming voids on the fibers. Coated gauzes exhibited optimum mechanical properties in terms of tensile strength and percent extension at break. GT coated dressings showed good fluid uptake and retention ability in-vitro. Test gauzes were non-hemolytic in nature, did not elicit any dermal toxicity on animals' skin and had the ability to protect against E. coli infection. In-vivo efficacy studies in rat femoral artery and liver laceration bleeding models indicated that gauzes coated with 4% GT were able to clot blood in least time (36.67 ± 3.33s and 40 ± 2.58s respectively) as compared to other gum combinations and commercially available dressing 'Surgispon® (103.3 ± 4.22s and 85 ± 5.62s respectively). Results of this study validate our initial findings of the potential of gum tragacanth to be developed into a suitable haemostatic product.

Composites Based on Gellan Gum, Alginate and Nisin-Enriched Lipid Nanoparticles for the Treatment of Infected Wounds

Due to growing antimicrobial resistance to antibiotics, novel methods of treatment of infected wounds are being searched for. The aim of this research was to develop a composite wound dressing based on natural polysaccharides, i.e., gellan gum (GG) and a mixture of GG and alginate (GG/Alg), containing lipid nanoparticles loaded with antibacterial peptide-nisin (NSN). NSN-loaded stearic acid-based nanoparticles (NP_NSN) were spherical with an average particle size of around 300 nm and were cytocompatible with L929 fibroblasts for up to 500 µg/mL. GG and GG/Alg sponges containing either free NSN (GG + NSN and GG/Alg + NSN) or NP_NSN (GG + NP_NSN and GG/Alg + NP_NSN) were highly porous with a high swelling capacity (swelling ratio above 2000%). Encapsulation of NSN within lipid nanoparticles significantly slowed down NSN release from GG-based samples for up to 24 h (as compared to GG + NSN). The most effective antimicrobial activity against Gram-positive Streptococcus pyogenes was observed for GG + NP_NSN, while in GG/Alg it was decreased by interactions between NSN and Alg, leading to NSN retention within the hydrogel matrix. All materials, except GG/Alg + NP_NSN, were cytocompatible with L929 fibroblasts and did not cause an observable delay in wound healing. We believe that the developed materials are promising for wound healing application and the treatment of bacterial infections in wounds.