Acacia gum polysaccharide based hydrogel wound dressings: Synthesis, characterization, drug delivery and biomedical properties
Graphical abstract
Introduction
Design of innovative bioactive materials for wound care is a necessity of the present era in order to accelerate wound healing processes. Mimicry of the human skin by the hydrogels has led to exploration of their potential as wound dressings materials. Nowadays, hydrogels have been widely accepted as biomaterial scaffolds for tissue-engineering applications due to their crosslinked three dimension structures which have ability to encapsulate cells and bioactive molecules, efficient mass transfer, and easily manipulated physical properties (Bonifacio, Gentile, Ferreira, Cometa, & Giglio, 2017; Fan et al., 2017 Shankar et al., 2017). Highly hydrated hydrogels provide ideally cellular microenvironments for cell proliferation and differentiation. Hydrogels also possess structural and functional similarities to the natural extracellular matrices (Paladini, Pollini, Sannino, & Ambrosio, 2015). Natural polymers have frequently been used to make hydrogel dressings for tissue-engineering applications owing to their biocompatibility, inherent biodegradability, and critical biological functions (Hoffman, 2012). Keeping in view the importance of natural polysaccharide based hydrogel in wound dressing applications, in the present work, an attempt has been made to design a hydrogel dressing using gum-acacia (GA), polyvinylpyrollidone [poly(NVP] and carbopol. Further, these hydrogel dressings have been loaded with antibiotic drug moxifloxacin to enhance their wound healing potential (Jacobsen et al., 2011). Hence, the proposed antibiotic drug loaded hydrogel wound dressings will not only provide protection from infection for longer period (due to antibiotic drug) but can also absorbed simulated wound fluid which is necessary for wound debridement and maintenance of moist wound environment for rapid wound healing. GA, poly(NVP) and carbopol are briefly discussed here.
Gum arabic is a dried exudation obtained from the stems and branches of Acacia Senegal or closely related species of acacia (fam. Leguminosae). It consists mainly of higher molecular weight polysaccharides and their calcium, magnesium and potassium salts, which on hydrolysis yield arabinose, galactose, rhamnose and glucuronic acid (FAO, 1999, Phillips, 1998; Idris, Williams, & Phillips, 1998). GA is a water soluble gum and forms solutions over a wide range of concentrations without becoming highly viscous (Cozic, Picton, Garda, Marlhoux, & Cerf, 2009). GA is a non-digestible food ingredient that has found many applications in the food and pharmaceutical industries. GA has strong anti-oxidant properties, and a major mechanism for the induction of renal or hepatic toxicities is the generation of free radicals (Ali, Ziada, & Blunden, 2009). Recently, it has been reported that gum acacia extract is haemostatic, non-haemolytic, and antibacterial in nature (Bhatnagar, Parwani, Sharma, Ganguli, & Bhatnagar, 2013). Carbopol is a mucoadhesive poly(acrylic acid) polymer which has been used in gel formation for transdermal drug delivery applications (Jana, Manna, Nayak, Sen, & Basu, 2014). On the other hand, poly(NVP) polymer is a water soluble, hydrophilic polymer and has been used in wound dressings materials. It has been found cytocompatible for human dermal fibroblasts and has significantly increased fibroblast viability (Shahbuddin, Bullock, MacNeil, & Rimmer, 2014). Poly(NVP) addition in the composite polymer matrix improved the blood compatibility of the biomaterials (Wetzels & Koole, 1999).
Section snippets
Materials
Gum acacia (GA), carbopol 940 (CP) [Loba Chemie Pvt. Ltd., Mumbai-India], and N-Vinylpyrollidone (NVP) [Merck Specialities Pvt. Ltd., Mumbai, India] were used as materials for the synthesis of polymers. Ammonium persulphate (APS) [Qualigens Fine Chemicals, Mumbai-India] was used as initiator, N,N-methylenebisacrylamide (NN-MBA) [Acros organics, New Jersey-USA] was used as crosslinker and glycerol [S.D. Fine Chemical Ltd., Mumbai-India] was used as plasticizer for the synthesis of these polymer
Characterization
Solid state 13C NMR spectrum of GA and GACVP is shown in Fig. 1a. In case of 13C NMR of crosslinked polymers the broad peak at δ = 178.448 can be attributed to carbonyl (CO) carbons of poly (NVP), carbopol and GA, and some adjacent smaller peaks may be due to different environment of the three carbonyl carbon present in the polymer matrix. Another broad peak of less intensity at δ = 105.213 was observed due to anomeric carbon of pyranose rings present in GA. Peaks around δ = 85.131 are characteristic
Conclusions
From the foregone discussion, it is concluded that the hydrogel dressings are porous in nature. The three dimensional porous structure is confirmed from cryo- SEM images of the hydrogel films. Release of moxifloxacin drug from the hydrogel dressing followed non-Fickian diffusion mechanism and release profile was best fitted in the Higuchi model. The polymer films showed antioxidant activity and absorbed wound fluid. The results of drug release studies and biomedical properties indicated that
Conflicts of interests
The authors declare that they have no conflicts of interests.
Acknowledgments
One of the author wishes to thank UGC, New Delhi, India for providing financial assistance in the work. (Letter No. F.17-40/08(SA-I), dated 27 April, 2012).
References (49)
- et al.
Kinetic release studies of nitrogen-containing bisphosphonate from gum acacia crosslinked hydrogels
International Journal of Biological Macromolecules
(2015) - et al.
Biological effects of gum arabic: A review of some recent research
Food and Chemical Toxicology
(2009) - et al.
Analysis of swelling behavior of poly (methacrylamide-co-methacrylic acid) hydrogels and effect of synthesis conditions on water uptake
Reactive and Functional Polymers
(2006) - et al.
Superoxide dismutase: Improved assays and an assay applicable to acrylamide gels
Analytical Biochemistry
(1971) - et al.
Encapsulation of proteins in hydrogel carrier systems for controlled drug delivery: Influence of network structure and drug size on release rate
Journal of Biotechnology
(2013) - et al.
Insight into halloysite nanotubes-loaded gellan gum hydrogels for soft tissue engineering applications
Carbohydrate Polymers
(2017) - et al.
Analysis of arabic gum: Study of degradation and water desorption processes
Food Hydrocolloids
(2009) - et al.
Wound dressings loaded with an anti-inflammatory juca (Libidibia ferrea) extract using supercritical carbon dioxide technology
The Journal of Supercritical Fluids
(2013) - et al.
Covalent and injectable chitosan-chondroitin sulfate hydrogels embedded with chitosan microspheres for drug delivery and tissue engineering
Materials Science and Engineering
(2017) Hydrogels for biomedical applications
Advanced Drug Delivery Reviews
(2012)