Development of a bioink using exopolysaccharide from Rhizobium sp. PRIM17

Biopolymers play a significant role in tissue engineering, including in the formulation of bioinks that require careful selection of the biopolymers having properties ideal for printability and supporting biological entities such as cells. Alginate is one of the most widely explored natural biopolymers for tissue engineering applications due to its biocompatibility, cross-linking ability, hydrophilic nature, and easy incorporation with other polymers. Here, a succinoglycan-like exopolysaccharide (EPS-R17) produced by a bacterial strain Rhizobium sp. PRIM17 was incorporated with alginate for the development of a bioink. The physicochemical characterization of EPS-R17 was performed before formulating the bioink with alginate. The bioink formulation was prepared by mixing different concentrations of EPS with an alginate solution at room temperature under sterile atmosphere. The prepared bioink was characterized for rheological properties, biocompatibility, and a bioplotting experiment was also conducted to mimick the extrusion bioprinting. The EPS-R17 was composed of glucose, galactose, and rhamnose with a molecular weight of 69.98 kDa. It was thermally stable up to 260 °C and showed characteristic FT-IR peaks (1723.3 cm^-1) for succinyl groups. The EPS-R17 showed biocompatibility with keratinocytes (HaCaT), and fibroblasts (HDF) in vitro. The rheological properties of EPS-R17-alginate bioink at different combinations showed shear thinning behavior at 25 and 37 °C. Amplitude sweep measurements showed the gel-like nature of the polymer combinations in the solution system superior to alginate or EPS-R17 alone. The combination of 1 % EPS-R17 and 1.5 % alginate showed good compressive strength and swelling behavior. Extrusion bioprinting mimicked using a bioplotting experiment showed the sustained cell viability in the polymer matrix of EPS-R17-alginate bioink. The results indicate that the EPS-R17 can be used in combination with alginate for bioinks for bioprinting applications for providing physical properties and favorable bioactivities.

Exopolysaccharide from the yeast Papiliotrema terrestris PT22AV for skin wound healing

INTRODUCTION

Exopolysaccharides (EPSs) are high-value functional biomaterials mainly produced by bacteria and fungi, with nutraceutical, therapeutic and industrial potentials.

OBJECTIVES

This study sought to characterize and assess the biological properties of the EPS produced by the yeast Papiliotrema terrestris PT22AV.

METHODS

After extracting the yeast's DNA and its molecular identification, the EPS from P. terrestris PT22AV strain was extracted and its physicochemical properties (structural, morphological, monosaccharide composition and molecular weight) were characterized. The EPS's in vitro biological activities and in vivo wound healing potential were also evaluated.

RESULTS

The obtained EPS was water-soluble and revealed an average molecular weight (M_w) of 202 kDa. Mannose and glucose with 97% and 3% molar percentages, respectively, constituted the EPS. In vitro antibacterial activity analysis of the extracted EPS exhibited antibacterial activity (>80%) against Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis at a concentration of 2 mg/mL. The EPS showed cytocompatibility against the human fibroblast and macrophage cell lines and the animal studies showed a dose-dependent wound healing capacity of the EPS with higher wound closure at 10 mg/mL compared to negative and positive control after 14 days.

CONCLUSION

The EPS from P. terrestris PT22AV could serve as a promising source of biocompatible macromolecules with potential for skin wound healing.

Development of a novel beta-glucan supplemented hydrogel spray formulation and wound healing efficacy in a db/db diabetic mouse model

To relief the severe economic and social burdens and patient suffering caused by the increasing incidence of chronic wounds, more effective treatments are urgently needed. In this study, we focused on developing a novel sprayable wound dressing with the active ingredient β-1,3/1,6-glucan (βG). Since βG is already available as the active ingredient in a commercial wound healing product provided as a hydrogel in a tube (βG-Gel), the sprayable format should bring clinical benefit by being easily sprayed onto wounds; whilst retaining βG-Gel's physical stability, biological safety and wound healing efficacy. Potentially sprayable βG hydrogels were therefore formulated, based on an experimental design setup. One spray formulation, named βG-Spray, was selected for further investigation, as it showed favorable rheological and spraying properties. The βG-Spray was furthermore found to be stable at room temperature for more than a year, retaining its rheological properties and sprayability. The cytotoxicity of βG-Spray in keratinocytes in vitro, was shown to be promising even at the highest tested concentration of 100 μg/ml. The βG-Spray also displayed favorable fluid affinity characteristics, with a capacity to both donate and absorb close to 10% fluid relative to its own weight. Finally, the βG-Spray was proven comparably effective to the commercial product, βG-Gel, and superior to both the water and the carrier controls (NoβG-Spray), in terms of its ability to promote wound healing in healing-impaired animals. Contraction was found to be the main wound closure mechanism responsible for the improvement seen in the βG-treatment groups (βG-Spray and βG-Gel). In conclusion, the novel sprayable βG formulation, confirmed its potential to expand the clinical use of βG as wound dressing.

Research status and hotspots of economic evaluation in nursing by co-word clustering analysis

Objective

The aim of this study is to discover research status and hotspots of economic evaluation (EE) in nursing area using co-word cluster analysis.

Methods

Medical Subject Heading (MeSH) term “cost–benefit analysis” was searched in PubMed and nursing journals were limited by the function of filter. The information of author, country, year, journal, and keywords of collected paper was extracted and exported to Bicomb 2.0 system, where high-frequency terms and other data could be further mined. SPSS 19.0 was used for cluster analysis to generate dendrogram.

Results

In all, 3,020 articles were found and 10,573 MeSH terms were detected; among them, 1,909 were MeSH major topics and generated 42 high-frequency terms. The consequence of dendrogram showed seven clusters, representing seven research hotspots: skin administration, infection prevention, education program, nurse education and management, EE research, neoplasm patient, and extension of nurse function.

Conclusions

Nursing EE research involved multiple aspects in nursing area, which is an important indicator for decision-making. Although the number of papers is increasing, the quality of study is not promising. Therefore, further study may be required to detect nurses’ knowledge of economic analysis method and their attitude to apply it into nursing research. More nursing economics course could carry out in nursing school or hospitals.

Cost-effectiveness of soluble beta-glucan gel in hard-to-heal wounds: an evaluation

OBJECTIVE

To evaluate the cost-effectiveness of a soluble beta-glucan-containing gel as short-term adjunct therapy in the treatment of hard-to-heal wounds in a UK community health-care setting.

METHODS

A comparative clinical evaluation involving consecutive patients treated for up to eight weeks with a beta-glucan-containing gel as adjunct to standard care. This was compared with consecutive patients as retrospective controls, and using the same standard care protocol from a year previously. The inclusion criteria was wounds that were slow-healing or stalled (<40% healing in four weeks).

RESULTS

A total of 300 patients took part. Complete follow-up at 24 weeks was available for 144 patients in the beta-glucan group, and 136 patients in the standard care group. At 24 weeks, the beta-glucan group had a 96% healing rate compared with 75% in the standard care group (p<0.001). The improvement in healing was associated with a reduction in the mean number of weeks of treatment per patient (7.2 and 10.7 for beta-glucan and standard care, respectively), and a reduction in the mean cost of treatment (£576 versus £685 for beta-glucan and standard care, respectively). Treatment costs included nursing time, prescription medications and dressings. In a subset of ulcer wounds (50% of the full sample), at 24 weeks the beta-glucan group had a 92% healing rate compared with 46% in the standard care group (p<0.001). Mean weeks of treatment were 10.4 versus 17.6, leading to a reduction in treatment cost of £388 per patient (£1227 versus £839) over 24 weeks.

CONCLUSION

The results of this evaluation suggest that short-term use of the beta-glucan gel as an adjunct to standard care on slow-healing wounds can shorten healing times and reduce NHS costs.

β-Glucans: Multi-Functional Modulator of Wound Healing

β-glucans are derived from a variety of sources including yeast, grain and fungus and belong to the class of drugs known as biological response modifiers. They possess a broad spectrum of biological activities that enhance immunity in humans. One promising area for β-glucans’ application is dermatology, including wound care. Topical applications of β-glucans are increasing, especially due to their pluripotent properties. Macrophages, keratinocytes and fibroblasts are considered the main target cells of β-glucans during wound healing. β-glucans enhance wound repair by increasing the infiltration of macrophages, which stimulates tissue granulation, collagen deposition and reepithelialization. β-glucan wound dressings represent a suitable wound healing agent, with great stability and resistance to wound proteases. This review summarizes the current knowledge and progress made on characterizing β-glucans’ wound healing properties in vitro and in vivo and their safety and efficacy in managing non-healing wounds or other chronic dermatological conditions and diseases.