Arabic Gum Grafted PEGDMA Hydrogels: Synthesis, Physico-Chemical Characterization and In-vitro Release of Hydrophobic Drug

Effectiveness of Using Gum Arabic for Co-Microencapsulation of Ruellia tuberosa L. and Tithonia diversifolia Extracts as Encapsulating Agent and Release Studies

This study used a combination of leaves extracts from Ruellia tuberosa L. and Tithonia diversifolia plants encapsulated using gum Arabic. The selection of leaves in medicinal plants because they are rich in bioactive compounds that provide health benefits. The encapsulation technique was microencapsulation through freeze-drying, since the nanoencapsulation for the plant extracts is unlikely to be conducted due to their large particle sizes. The resulting microcapsules were then tested their biological activities in vitro. Several conditions affect microcapsules' production, including pH, gum Arabic concentration, and stirring time were assessed. The optimum conditions were chosen based on the highest encapsulation efficiency. The results showed that the optimum microcapsules preparation was achived at pH 5, gum Arabic concentration of 4% (w/v), and stirring time of 60 min with an encapsulation efficiency of 84.29%. The in vitro assays include inhibition of alpha-amylase and antioxidant activities, resulted in the respective IC50 values of 54.74 μg/mL and 152.74 μg/mL. Releases of bioactive compounds from the microcapsules were investigated under pH 2.2 and pH 7.4 from 30 to 120 min. Results indicated a release of 43.10% at pH 2.2 and 42.26% at pH 7.4 during 120 min, demonstrating the controlled release behavior of the encapsulated bioactive compounds; nonetheless, their release behavior was not pH-dependent. This study confirms that microencapsulation has an important role in the development of plant extracts with maintained biological functions as well as maintaining their stability.

Polysaccharides gums in drug delivery systems: A review

For the drug delivery system, drug carriers' selection is critical to the drug's success in reaching the desired target. Drug carriers from natural biopolymers are preferred over synthetic materials due to their biocompatibility. The use of polysaccharide gums in the drug delivery system has received considerable attention in recent years. Polysaccharide gums are renewable resources and abundantly found in nature. They could be isolated from marine algae, microorganisms, and higher plants. In terms of carbohydrates, the gums are water-soluble, non-starch polysaccharides with high commercial value. Polysaccharide gums are widely used for controlled-release products, capsules, medicinal binders, wound healing agents, capsules, and tablet excipients. One of the essential applications of polysaccharide gum is drug delivery systems. The various kinds of polysaccharide gums obtained from different plants, marine algae, and microorganisms for the drug delivery system application are discussed comprehensively in this review paper.

Full factorial design of experiment-based and response surface methodology approach for evaluating variation in uniaxial compressive mechanical properties, and biocompatibility of photocurable PEGDMA-based scaffolds

The goal of this study is to fabricate biocompatible and minimally invasive bone tissue engineering scaffolds that allowin situphotocuring and further investigate the effect on the mechanical properties of the scaffold due to the prevailing conditions around defect sites, such as the shift in pH from the physiological environment and swelling due to accumulation of fluids during inflammation. A novel approach of incorporating a general full factorial design of experiment (DOE) model to study the effect of the local environment of the tissue defect on the mechanical properties of these injectable and photocurable scaffolds has been formulated. Moreover, the cross-interaction between factors, such as pH and immersion time, was studied as an effect on the response variable. This study encompasses the fabrication and uniaxial mechanical testing of polyethylene glycol dimethacrylate (PEGDMA) scaffolds for injectable tissue engineering applications, along with the loss in weight of the scaffolds over 72 h in a varying pH environment that mimicsin vivoconditions around a defect. The DOE model was constructed with three factors: the combination of PEGDMA and nano-hydroxyapatite referred to as biopolymer blend, the pH of the buffer solution used for immersing the scaffolds, and the immersion time of the scaffolds in the buffer solution. The response variables recorded were compressive modulus, compressive strength, and the weight loss of the scaffolds over 72 h of immersion in phosphate-buffered saline at respective pH. The statistical model analysis provided adequate information in explaining a strong interaction of the factors on the response variables. Further, it revealed a significant cross-interaction between the factors. The factors such as the biopolymer blend and pH of the buffer solution significantly affected the response variables, compressive modulus and strength. At the same time, the immersion time had a strong effect on the loss in weight from the scaffolds over 72 h of soaking in the buffer solution. The biocompatibility study done using a set of fluorescent dyes for these tissue scaffolds highlighted an enhancement in the pre-osteoblasts (OB-6) cell attachment over time up to day 14. The representative fluorescent images revealed an increase in cell attachment activity over time. This study has opened a new horizon in optimizing the factors represented in the DOE model for tunable PEGDMA-based injectable scaffold systems with enhanced bioactivity.

Naringin-loaded Arabic gum/pectin hydrogel as a potential wound healing material

Wound healing is a complicated cellular process with overlapping phases. Naringin (NAR); a flavanone glycoside, possesses numerous pharmacological effects such as anti-inflammatory, antioxidant and anti-apoptotic effects. In the current study, Arabic gum (AG)/pectin hydrogel was utilized to encapsulate NAR. Drug-loaded AG/pectin hydrogel exhibited excellent EE% of about 99.88 ± 0.096 and high DL% of about 16.64 ± 0.013. The formulated drug-loaded hydrogel was characterized using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and Zetasizer analyzer, besides determination of equilibrium degree of swelling (EDS%). Afterwards, wound healing potential of NAR-loaded AG/pectin hydrogel was evaluated in an in vivo animal model. Results manifested that NAR-loaded AG/pectin hydrogel was able to accelerate wound healing in terms of enhanced angiogenesis, re-epithelialization and collagen deposition. Furthermore, it significantly (P < 0.001) down-regulated the mRNA expression of inflammatory mediators (TNF-α) and apoptosis (BAX). In addition, NAR-loaded AG/pectin hydrogel was found to possess potent antioxidant activity as it enhanced the levels of SOD and GSH, besides decreasing the levels of MPO, MDA and nitrite. These data suggest that NAR-loaded AG/pectin hydrogel could be utilized in wound healing applications.

System optimization of an embedding protocol to immobilize cells from Candida bombicola to improve the efficiency of sophorolipids production

This study introduces the implication of immobilization technology in the fermentation process of sophorolipids (SLs) production by Candida bombicola. Firstly, an evaluation system was established for the performance of embedding immobilization and subsequently applied to guide the optimization of operating conditions for sodium alginate immobilization. Correspondingly, the SLs titer increased from 11.4 g/L to 14.6 g/L. Secondly, polyvinyl alcohol was introduced for composite embedding to improve the stability of immobilized beads. Then exogenous addition of 1.5% diatomite further enhanced the fermentation performance of immobilized cells, thereby increasing the SLs titer to 35.9 g/L, which was 2.1 times higher than the original immobilized cells method. Finally, the immobilized cells were tested for three repeated batches of SLs fermentation. Compared to the free cells fermentation, the SLs productivity and substrate conversion rate were increased by 35.5% and 9.1%, respectively. The obtained results showed high potential for application on an industrial scale.