Changes in Structural and Rheological Properties of Guar Gum Particles in Fluidized-Bed Agglomeration: Effect of Sucrose Binder Concentration

One-pot method to prepare the guar gum hydrogel dressing and its application in wound repair

BackgroundThe skin serves as a critical barrier, safeguarding the body against external threats including bacteria, viruses, and ultraviolet (UV) radiation. Compromised skin integrity can result in pain, hinder daily activities, and elevate the risk of infections. Clinically, dressings are the conventional treatment for skin injuries. However, these often necessitate frequent replacements and may exacerbate wound trauma during removal. Therefore, there is growing interest in developing innovative dressings such as hydrogels, which are celebrated for their softness, adaptability, permeability, and capacity to sustain a moist wound environment. Guar gum, a galactomannan polysaccharide extensively utilized in the food and biomedical sectors, forms highly viscous, biocompatible hydrogels that are promising for medical applications including capsules and wound dressings. Nonetheless, the mechanical strength and antimicrobial properties of guar gum hydrogels require enhancements for optimal medical efficacy.ObjectiveThis study explores the fortification of guar gum (GG) hydrogels with tannic acid (TA) and citric acid (CA), which are known for their antibacterial, anti-inflammatory, and antioxidant properties, to develop injectable, antimicrobial hydrogel dressings.MethodsEmploying a one-pot synthesis method, this research aimed to create dressings for treating skin injuries in murine models. The hydrogels were characterized using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR), assessed for antibacterial efficacy against Staphylococcus aureus, and evaluated for biocompatibility and therapeutic effectiveness in mice with full-thickness skin injuries.ResultsThe results demonstrated successful cross-linking, structural stability, and significant enhancement in wound healing, indicating the potential of these GG-CA-TA hydrogel dressings to broaden the scope of guar gum applications in clinical skin restoration.ConclusionIn this study, a kind of Guar gum hydrogel was successfully synthesized by one-pot method, which has great potential in clinical skin repair.

Gallic acid-guar gum and chitosan-based polyelectrolyte complex film exhibited enhanced wound healing in full-thickness excision wound model

Recently, there has been a great interest in the development of innovative wound dressing materials based on natural bioactives, as they can accelerate the healing process and address the issues related to traditional wound dressings. The current study focuses on developing a novel derivative of guar gum (GG) and gallic acid (GA) using a simple, free radical-mediated polymerization reaction aimed at enhancing the antioxidant properties of GG. Multiple spectroscopic investigations were performed to validate the GA-GG conjugate. NMR and FTIR confirmed GA integration, UV spectroscopy indicated changes in electronic transition, DSC analysis suggested a reduction in crystallinity, and XRD revealed structural modifications. SEM revealed a porous structure that reflected its polymerized nature. Due to inadequate mechanical strength and film-forming ability of the synthesized GA-GG conjugate, polyelectrolyte complexation method using chitosan was explored to form a polyelectrolyte complex (PEC) film. The film exhibited a high swelling rate, excellent antioxidant properties, and was both hemocompatible and exhibited improved antimicrobial properties. In vitro, in ovo, and in vivo characterizations were performed to compare the performance of these biocomposite films to those of their counterparts. It promoted angiogenesis in the chick yolk sac membrane and demonstrated good cytocompatibility in cell proliferation studies on the viability of the L929 mouse fibroblast cell line. In vivo wound healing efficacy of the PEC film in wound closure was 94.5% as compared to the untreated disease control group (p < 0.001). This work highlights the development of an innovative GA-GG conjugate/chitosan PEC-based film with significant potential for wound healing applications.

Effect of fluidized-bed agglomeration with sugar binders on physical, crystallinity, thermal, and pasting properties of native potato starch

Fluidized-bed agglomeration of native potato starch (NPS) with sugar binders [maltodextrin (MD) and lactose] produced larger particles with a more porous and diverse shape. Moreover, the agglomerated potato starch (APS) exhibited improved flowability and solubility. All powders displayed a B-type X-ray diffraction pattern. Although lactose did not impact the crystallinity of APS, that of APS prepared with MD decreased as the MD concentration increased. NPS showed higher gelatinization temperatures than APS prepared with distilled water (the control). Moreover, as binder concentration increased, the gelatinization temperatures and enthalpy of APS increased and decreased, respectively, indicating a delay in gelatinization. Similar results were observed with the pasting properties, wherein APS with sugar binders exhibited lower pasting, breakdown, setback, and final viscosities compared to the control. These were likely a result of decreased amylose leaching from the granules during heating due to the presence of sugar.

Rheological and tribological properties of native potato starch agglomerated by fluidized bed granulator

We explored the rheological and tribological properties of potato starch agglomerated with a sugar binder (maltodextrin or lactose) at various concentrations by using a fluidized bed granulator. The magnitudes of consistency index and apparent viscosity of agglomerated potato starch (APS) decreased as the binder concentration was increased. Moreover, APS with a sugar binder showed lower viscoelastic moduli and higher tan δ values compared to APS with water as the binder (the control). The gel strength of all agglomerates decreased as the sugar concentration was increased. All samples showed anti-thixotropic behavior, and especially, APS with 20 % lactose showed a small anti-thixotropic area. Utilizing the Arrhenius equation clearly elucidated the effect of temperature on the apparent viscosity of all the samples. Although the maltodextrin concentration had little influence on the activation energy of APS, it increased as the lactose concentration was increased. APS samples with a sugar binder showed greater friction coefficient values compared to the control, with maltodextrin having a significant impact. The findings indicate that the rheological and tribological properties of APS rely on the type and concentration of sugar binder.