Evaluating the Impact of Vitamin D3 on NF-κB and JAK/STAT Signaling Pathways in Drosophila melanogaster.

This study delved into the consequences of prolonged administration of vitamin D3 on innate immune systems, particularly NF-κB and JAK/STAT, in Drosophila melanogaster. The outcomes indicated that vitamin D3 treatment exhibited a notable capacity to improve the survival of adult flies with compromised immune functions, a condition induced by the loss of PGRP-LB, particularly when the flies were exposed to heat-killed Escherichia coli. The PGRP-LBΔ mutant line that was treated with heat-killed E. coli experienced reduced survival. Treatment of heat-killed E. coli-treated PGRP-LBΔ with vitamin D3 resulted in improved survival, and this phenotypic feature might be due to the downregulation of gene expression in the NF-κB and JAK/STAT pathways. However, a higher concentration of vitamin D3 was associated with decreased survival, potentially linked to intricate immunological responses. The research also underscored the influence of vitamin D3 on the expression of antioxidant genes, sod1 and sod2, indicating an augmented resistance to oxidative stress. Further, this study revealed the effect of vitamin D3 on the reproductive status of the autoinflammatory model, showing an increase in pupae and adult flies with a treatment of 10 mM vitamin D3, suggesting the potential benefits of vitamin D3 on the reproductive profile. Overall, this study provides preliminary insights into the complex interactions between vitamin D3, immune pathways, oxidative responses in the cell, and reproduction in Drosophila.

Validation of spectrophotometric method to quantify chloramphenicol in fluid and rat skin tissue mimicking infection environment: Application to in vitro release and ex vivo dermatokinetic studies from dissolving microneedle loaded microparticle sensitive bacteria.

Cellulitis is a common dermis/subcutaneous tissue skin infection and shared global disease burden, with a higher incidence for males and people aged 45-64 years. Application therapy of chloramphenicol (CHL) has been hindered because of its toxicity and limited penetration into the skin. In this research, CHL was developed into a bacterially sensitive microparticles which were further incorporated into a microneedle system to increase penetration. To support this formulation, in this study, UV-vis spectrophotometry method was validated in methanol, polyvinyl alcohol (PVA) 1%, phosphate buffered saline (PBS), tryptic soy broth (TSB) (fluid-mimicking infection), and skin tissue to quantify amount of CHL. The developed analytical method was subsequently validated according to ICH guidelines. The results obtained showed that the correlation coefficients were linear ≥0.9934. The values of LLOQ inside the methanol, PVA 1%, PBS, TSB, and skin tissue were 7.20 µg/mL, 4.40 µg/mL, 8.18 µg/mL, 387.48 µg/mL, and 7.27 µg/mL, respectively. The accuracy and precision of the developed method were prominent. These methods were successfully applied to quantify the amount of CHL in microparticle and microneedle system in fluid and tissue skin infection. The result showed the high drug release microparticle sensitive bacteria, and high drug retention in ex vivo dermatokinetic evaluation in rat skin tissue containing bacterial infection. This was due to the presence of Staphylococcus aureus bacteria culture that produced lipase enzymes, playing a role in lysing microparticle matrix to develop selectively delivery antimicrobials. A further analytical method needs to be matured to quantify CHL inside the in vivo studies.

Enhancement in Site-Specific Delivery of Chloramphenicol Using Bacterially Sensitive Microparticle Loaded Into Dissolving Microneedle: Potential For Enhanced Effectiveness Treatment of Cellulitis.

One of the biggest challenges in infectious disease treatment is the existence of bacterial infections in underskin wound tissue, such as cellulitis. Compared to other treatments, it is harder for antibacterial drugs to penetrate the physical barrier on the affected skin with a nonspecific target, making conventional therapy for cellulitis infection more difficult and considered. In this novel research, we pioneer a combined strategy of dissolving microneedles (MNs) and bacteria-sensitive microparticles (MPs) for enhanced penetration and targeted delivery of chloramphenicol (CHL) to the infection site specifically. The polycaprolactone polymer was used to make MPs because of its sensitivity to bacterial enzyme stimuli. The best microparticle formulation was discovered and optimized using the Design-Expert application. Furthermore, this study evaluated the antibacterial activity of MPs in vitro and in vivo on the mutant Drosophila larval infection model. This strategy shows improvement in the antibacterial activity of MPs and higher retention duration compared to conventional cream formulation, and the inclusion of these MPs into dissolving MNs was able to greatly improve the dermatokinetic characteristics of CHL in ex vivo evaluation. Importantly, the antimicrobial efficacy in an ex vivo infection model demonstrated that, following the use of this strategy, bacterial bioburdens decreased by up to 99.99% after 24 h. The findings offered a proof of concept for the enhancement of CHL dermatokinetic profiles and antimicrobial activities after its preparation into bacteria-sensitive MPs and distribution by MNs. Future research should investigate in vivo effectiveness in an appropriate animal model.

Development of chloramphenicol wound dressing protein-based microparticles in chitosan hydrogel system for improved effectiveness of dermal wound therapy.

Skin wounds have been reported to increase the number of microbial colonies susceptible to infection. Treatments using oral antibiotics have been limited due to their toxicity and hydrophobic characteristics. In this study, we developed a formulation of chloramphenicol microparticles (CPL MPs), which was modified into chitosan hydrogel to increase treatment efficiency in targeting infections and creating an optimal environment to support the healing process. CPL MPs were prepared by a cross-linker stabilized method using whey protein (WPI) biopolymer, and the CPL MPs hydrogel was designed using chitosan biopolymer. Based on the result, CPL-loaded MPs showed desired physical and encapsulation characteristics. In the in vitro study, drug release of CPL MPs in simulated wound fluid represented approximately 99.40 ± 7.01 % of the system after 24 h. The antibacterial activity of CPL-loaded MPs formulation (MIC value 12.5 µg/mL, MBC 25 µg/mL) was effective as MIC concentration increased. Furthermore, the formulation of CPL MPs into hydrogel showed a better dermatokinetic profile compared to hydrogel with pure CPL. Interestingly, the antibacterial activity of the ex vivo infection model showed that Staphylococcus aureus activity decreased by up to 99.98 % after 24 h administration of CPL MPs hydrogel when compared to pure-CPL hydrogel and blank hydrogel. These studies have confirmed that incorporating CPL MPs into hydrogel can provide a promising approach to skin infection treatment.

Development of chloramphenicol whey protein-based microparticles incorporated into thermoresponsive in situ hydrogels for improved wound healing treatment.

This study focused on the incorporation ofchloramphenicol (CAP)intowhey protein (WPI)(CAP-MPs) and was further formulated into a thermoresponsivein situgel for wound healing treatment.CAP microparticleswereproduced by two steps emulsification process.The modification ofthe mixing time and speed, as well as the variation of WPI and CAP concentration, resulted in various particle sizes(0.95 ± 0.07to 8.94 ± 0.32 µm). The optimum formulation was achieved using 15 % WPI in water, and 2 mL CAP in propylene glycol withatotal amount in the mixture was 100 mg, and 5 % oil phase, with homogenization time and speed at 15 min and 7500 rpm, respectively. The characterization of CAP-MP's showed PDI values at 0.110 ± 0.007, drug entrapment efficiency at70.64 ± 1.12 %,and drug loading at 8.80 ± 0.12 %.SEM analysis of CAP-MPs showedspherical, uniform particlesdispersed across the surface of the emulsion droplets.FTIR analysis showed strong development of hydrogen bonds proving the encapsulation was effective. Pluronic® F127, Pluronic® F68, and hydroxypropyl methylcellulose (HPMC)were used for the thermoresponsive hydrogel formulation with desired properties. The gel formulationcouldprovideliquid form at room temperature (25 °C) andformagel at 31 °C.This optimum formula was able to increase the bioadhesivity (28160.92 ± 3902.09 dyne/cm2) as well as the percentage of gels skin occlusivity after 24 h (32.82 ± 0.004),and to be considered, it did not show hemolytic activities. In anex vivoantibacterial activity, this combination approach showed a 99.95 % reduction in theStaphylococcus aureus(SA) population.