Spawning Performance and Sex Steroid Levels in Female Pikeperch Sander lucioperca Treated with Poly(lactic-co-glycolic acid) Microparticles

Pikeperch Sander lucioperca is a piscivorous species considered a promising candidate for the diversification of intensive aquaculture. This study aimed to determine the effect of a sustained-release delivery system incorporating mammalian gonadotropin-releasing hormone agonist (mGnRHa) into poly(lactic-co-glycolic acid) (PLGA) microparticles on the sex steroid levels and aspects of artificial reproduction of pikeperch. Fish were divided into four groups and injected with 20 µg mGnRHa/kg, 5-day release microparticles encapsulated with 5 µg GnRHa/kg BW (PLGA 5), 20 µg GnRHa/kg (PLGA 20), or 1 mL/kg 0.9% NaCl (control). Cumulative percentage ovulation was 100% in the PLGA 5 group, significantly higher than in other tested groups. No differences among groups were observed in latency or fecundity. The level of 11-ketotestosterone (11-KT) peaked at 40 h post-injection, and was sustained during ovulation, in all treated groups. The 17β-estradiol (E2) concentration increased in the mGnRHa-only group immediately after hormone injection, while both PLGA groups showed a reduction in E2 after injection, continuing to decrease until ovulation. A low dose of mGnRHa in PLGA microparticles significantly improves induction of ovulation and results in acceptable reproductive performance, which may positively affect pikeperch production under controlled conditions.

Antimicrobial Susceptibility of Persister Biofilm Cells of Bacillus cereus and Pseudomonas fluorescens

The present study evaluates the antimicrobial susceptibility of persister cells of Bacillus cereus and Pseudomonas fluorescens after their regrowth in suspension and as biofilms. Two conventional (benzalkonium chloride—BAC and peracetic acid—PAA) and two emerging biocides (glycolic acid—GA and glyoxal—GO) were selected for this study. Persister cells resulted from biofilms subjected to a critical treatment using the selected biocides. All biocide treatments developed B. cereus persister cells, except PAA that effectively reduced the levels of vegetative cells and endospores. P. fluorescens persister cells comprise viable and viable but non-culturable cells. Afterwards, persister cells were regrown in suspension and in biofilms and were subjected to a second biocide treatment. In general, planktonic cultures of regrown persister cells in suspension lost their antimicrobial tolerance, for both bacteria. Regrown biofilms of persister cells had antimicrobial susceptibility close to those regrown biofilms of biocide-untreated cells, except for regrown biofilms of persister P. fluorescens after BAC treatment, which demonstrated increased antimicrobial tolerance. The most active biocide against persister cells was PAA, which did not promote changes in susceptibility after their regrowth. In conclusion, persister cells are ubiquitous within biofilms and survive after critical biocide treatment. The descendant planktonic and biofilms populations showed similar properties as the original ones.

In vitro drug release and antibacterial activity evaluation of silk fibroin coated vancomycin hydrochloride loaded poly (lactic-co-glycolic acid) (PLGA) sustained release microspheres

Currently, the treatment of osteomyelitis poses a great challenge to clinical orthopedics. The use of biodegradable materials combined with antibiotics provides a completely new option for the treatment of osteomyelitis. In this study, vancomycin hydrochloride (VANCO) loaded poly (lactic-co-glycolic acid) (PLGA) microspheres were prepared by a double emulsion solvent evaporation method, and the in vitro drug release behaviors of the drug loaded microspheres were explored after coating with different concentrations of silk fibroin (SF). Drug loading, encapsulation efficiency, Scanning electron microscopy, particle size analysis, Fourier transform infrared spectroscopy, hydrophilicity, in vitro drug release, and in vitro antibacterial activity were evaluated. The results showed that the drug loading of vancomycin loaded PLGA microspheres was (24.11 ±1.72)%, and the encapsulation efficiency was (48.21 ±3.44)%. The in vitro drug release indicated that the drug loaded microspheres showed an obvious initial burst release, and the drug loaded microspheres coated with SF could alleviate the initial burst release in varying degrees. It also can reduce the amount of cumulative drug release, and the effect of microspheres coated with 0.1% concentration of SF is the best. The time of in vitro drug release in different groups of drug loaded microspheres can be up to 28 days. The microspheres coated with (0.1%SF) or without (0%SF) SF showed a cumulative release of (82.50±3.51)% and (67.70±3.81)%,respectively. Therefore, the surface coating with SF of vancomycin loaded microspheres can alleviate the initial burst release, reduce the cumulative drug release, potentially prolong the drug action time, and improve the anti-infection effect.

Enhanced Anti-Proliferative Effect of Carboplatin in Ovarian Cancer Cells Exploiting Chitosan – Poly (lactic glycolic acid) Nanoparticles.

Objective: The aim of the present article was to enhance the therapeutic efficacy of carboplatin (CP) using the formulation of chitosan – poly (lactic glycolic acid) nanoparticles (CS-PLGA NPs). Methods: Nanoparticles were synthesized by an ionic gelation method and were characterized for their morphology, particle size, and surface potential measurements by TEM and zeta sizer. This study was highlighted for the evaluation of drug entrapment, loading and in vitro drug release capabilities of the prepared nanoparticles by spectrophotometric analysis. The stability study was also conducted after 3 months for their particle size, zeta potential, drug loading and encapsulation efficiencies. Further, ovarian cancer cell line PEO1 were used to evaluate the toxicity and efficacy of nano-formulation by MTT assay. Further, the study was evaluated for apoptosis using flow cytometric analysis. Result: The CS-PLGA-CP NPs were uniform and spherical in shape. The particle size and zeta potential of CS-PLGA-CP NPs were measured 156 ± 6.8 nm and +52 ± 2.4 mV, respectively. High encapsulation (87.4 ± 4.5 %) and controlled retention capacities confirmed the efficiency of the prepared nanoparticles in a time and dose dependant manner. The cytotoxicity assay results also showed that CS-PLGA-CP NPs has high efficiency on PEO1 cells compared to the free drug. The flow cytometric result showed 64.25 % of the PEO1 cells were apoptotic and 8.42 % were necrotic when treated with CS-PLGA-CP NPs. Conclusion: Chitosan-PLGA combinational polymeric nanoparticles were not only steady but also non-toxic. Our experiments revealed that the chitosan- PLGA nanoparticles could be used as a challenging vehicle candidate for drug delivery for the therapeutic treatment of ovarian cancer.

Evaluation of Effect of Biologically Synthesized Ethanolic Extract of Propolis-Loaded Poly(-Lactic-co-Glycolic Acid) Nanoparticles on Wound Healing in Diabetic Rats

Wound healing is interaction of a complex cascade of cellular/biochemical actions leading to restoration of structural and functional integrity with regain of injured tissues strength. This study was aimed at evaluation of application of ethanolic extract of propolis-loaded poly(-lactic-co-glycolic acid) nanoparticles (EEP-PLGA NPs) on wound healing in diabetic rats. Sixty rats were randomized into four groups of 15 rats each: In control group (Control) diabetic wound was treated with normal saline. In Carrier 1 group diabetic wound was treated with PLGA nanoparticles based solution. In Carrier 2 group the diabetic wound was treated with EEP. In Treatment group animals received EEP-PLGA NPs on the wound. Wound size was measured on 7, 14 and 21 days after surgery. The expression of p53, bcl-2, Caspase III, were evaluated using reverse-transcription PCR and Immunohistochemical staining. The Treatment group had significantly reduced the wound size compared to other groups ( P = 0.001). histological and morphometric studies, and mean rank of the qualitative studies demonstrated that there was significant difference between Treatment group and other groups ( P < .05). Observations demonstrated that ethanolic extract of propolis-loaded PLGA nanoparticles significantly shortened the inflammatory phase and accelerated the cellular proliferation. Accordingly, the animals in Treatment group revealed significantly ( P < .05) higher fibroblast distribution/one mm2 of wound area and rapid re epithelialization. The mRNA levels of bcl-2, p53 and caspase III were remarkably ( P < .05) higher in Treatment group compared to control and animals. The immunohistochemical analyzes confirmed the RT-PCR findings. EEP-PLGA NPs offered potential advantages in wound healing acceleration and improvement through angiogenesis stimulation, fibroblast proliferation and granulation tissue formation in early days of healing phases, acceleration in diabetic wound repair associated with earlier wound contraction and stability of damaged area by rearrangement of granulation tissue and collagen fibers.

Chitosan/poly(lactic-co-glycolic)acid Nanoparticle Formulations with Finely-Tuned Size Distributions for Enhanced Mucoadhesion

Non-parenteral drug delivery systems using biomaterials have advantages over traditional parenteral strategies. For ocular and intranasal delivery, nanoparticulate systems must bind to and permeate through mucosal epithelium and other biological barriers. The incorporation of mucoadhesive and permeation-enhancing biomaterials such as chitosan facilitate this, but tend to increase the size and polydispersity of the nanoparticles, making practical optimization and implementation of mucoadhesive nanoparticle formulations a challenge. In this study, we adjusted key poly(lactic-co-glycolic) acid (PLGA) nanoparticle formulation parameters including the organic solvent and co-solvent, the concentration of polymer in the organic phase, the composition of the aqueous phase, the sonication amplitude, and the inclusion of chitosan in the aqueous phase. By doing so, we prepared four statistically unique size groups of PLGA NPs and equally-sized chitosan-PLGA NP counterparts. We loaded simvastatin, a candidate for novel ocular and intranasal delivery systems, into the nanoparticles to investigate the effects of size and surface modification on drug loading and release, and we quantified size- and surface-dependent changes in mucoadhesion in vitro. These methods and findings will contribute to the advancement of mucoadhesive nanoformulations for ocular and nose-to-brain drug delivery.

Dissolving microneedle-encapsulated drug-loaded nanoparticles and recombinant humanized collagen type III for the treatment of chronic wound via anti-inflammation and enhanced cell proliferation and angiogenesis

The first recombinant humanized collagen type III (rhCol III) and naproxen (Nap) loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles incorporated hyaluronic acid (HA) microneedle (MN) was fabricated for diabetic chronic wounds therapy.

Effect of the Wells–Dawson phosphomolybdic heteropolyacid on the conversion of glucose into glycolic acid

The Wells–Dawson phosphomolybdic heteropolyacid had high activity and selectivity in the epimerization of glucose into mannose and the [2 + 4] retro-aldol reaction of glucose/mannose.