Development of an injectable PHBV microparticles-GG hydrogel hybrid system for regenerative medicine

Uncontrollable displacements that greatly affect the concentration of active agents at the target tissues are among a major limitation of the use of microparticulate drug delivery systems (DDS). Under this context a biphasic injectable DDS combining poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) microparticles (MPs) and a gellan gum (GG) injectable hydrogel is herein proposed for the localized delivery and long-term retention of MPs carrying hydrophilic and hydrophobic model active agents. A double emulsion-solvent evaporation method was adopted to develop the PHBV MPs, carrying bovine serum albumin (BSA) or dexamethasone (Dex) as hydrophilic and hydrophobic active agents’ models, respectively. Moreover, this method was modified, together with the properties of the hydrogel to tailor the delivery profile of the active agents. Variations of the composition of the organic phase during the process allowed tuning surface topography, particle size distribution and core porosity of the PHBV MPs and, thus, the in vitro release profile of Dex but not of BSA. Besides, after embedding hydrogels of higher GG concentration led to a slower and more sustained release of both active agents, independently of the processing conditions of the microparticulate system.The authors would like to acknowledge the Project RL1 - ABMR - NORTE-01-0124-FEDER-000016 co-financed by North Portugal Regional Operational Programme (ON.2 - O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF). This work was partially supported by European Research Council grant agreement ERC-2012-ADG 20120216-321266 for project ComplexiTE

Epithelial downgrowth leading to graft rejection after penetrating keratoplasty

Publisher Copyright: © The Author(s) 2022.Purpose: To report a case of epithelial downgrowth after penetrating keratoplasty. Case description: A 58-year-old man presented with graft rejection in his three-month-old, repeat penetrating keratoplasty. Examination revealed centripetal opacification of the posterior cornea due to deep epithelization. He had new retro-corneal membranes and anterior uveitis. Specular microscopy and anterior segment optical coherence tomography were performed, and a clinical diagnosis of epithelial downgrowth was made. The patient had intracameral injections with 5-fluorouracil (5FU) and achieved resolution of intraocular findings after treatment. Conclusions: Epithelial downgrowth is an uncommon complication of penetrating keratoplasty. It affects the patients’ visual acuity and graft survival. Clinical observation is preferred in severe cases due to the high risk of intraocular damage; intracameral 5FU promises to be a good option in these cases.Peer reviewe

Inhibition of HMG-CoA reductase activity and cholesterol permeation through Caco-2 cells by caffeoylquinic acids from Vernonia condensata leaves

AbstractThe aim of this study was to provide scientific knowledge to support the use of Vernonia condensata Baker, Asteraceae, beverages for their alleged hypocholesterolemic properties by testing their action as HMG-CoA reductase inhibitors and their capacity to lower dietary cholesterol permeation. Chlorogenic acid, and other caffeoylquinic acids derivatives were identified as the main components of these beverages by LC–MS/MS. No changes in the composition were notice after the in vitro gastrointestinal digestion and no toxicity against Caco-2 and HepG2 cell lines was detected. Cholesterol permeation through Caco-2 monolayers was reduced in 37% in the presence of these herbal teas, and the caffeoylquinic acids permeated the monolayers in 30–40% of their initial amount in 6h. HMG-CoA reductase activity was reduced with these beverages, showing an IC50 of 217μgml−1. It was concluded that caffeoylquinic acids, the major components, justified 98% of the enzyme inhibition measured

Water Adsorption Effect on Carbon Molecular Sieve Membranes in H2-CH4 Mixture at High Pressure

Carbon molecular sieve membranes (CMSMs) are emerging as promising solution to overcome the drawbacks of Pd-based membranes for H2 separation since (i) they are relatively easy to manufacture; (ii) they have low production and raw material costs; (iii) and they can work at conditions where polymeric and palladium membranes are not stable. In this work CMSMs have been investigated in pure gas and gas mixture tests for a proper understanding of the permeation mechanism, selectivity and purity towards hydrogen. No mass transfer limitations have been observed with these membranes, which represents an important advantage compared to Pd-Ag membranes, which suffer from concentration polarization especially at high pressure and low hydrogen concentrations. H2, CH4, CO2 and N2 permeation at high pressures and different temperatures in presence of dry and humidified stream (from ambient and water vapour) have been carried out to investigate the effect of the presence of water in the feed stream. Diffusion is the main mechanism observed for hydrogen, while methane, nitrogen and especially carbon dioxide permeate through adsorption-diffusion at low temperatures and high pressures. Finally, H2 permeation from H2-CH4 mixtures in presence of water has been compared at different temperatures and pressure, which demonstrates that water adsorption is an essential parameter to improve the performance of carbon molecular sieve membranes, especially when working at high temperature. Indeed, a hydrogen purity of 98.95% from 10% H2—90% CH4 was achieved. The main aim of this work is to understand the permeation mechanisms of CMSMs in different operating conditions and find the best conditions to optimize the separation of hydrogen.This project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking under grant Agreement no. 700355. This Joint Undertaking receves support from the European Union´s Horizon 2020 research

A combined approach for comparative exoproteome analysis of Corynebacterium pseudotuberculosis

Background: Bacterial exported proteins represent key components of the host-pathogen interplay. Hence, we sought to implement a combined approach for characterizing the entire exoproteome of the pathogenic bacterium Corynebacterium pseudotuberculosis, the etiological agent of caseous lymphadenitis (CLA) in sheep and goats. Results: An optimized protocol of three-phase partitioning (TPP) was used to obtain the C. pseudotuberculosis exoproteins, and a newly introduced method of data-independent MS acquisition (LC-MSE) was employed for protein identification and label-free quantification. Additionally, the recently developed tool SurfG+ was used for in silico prediction of sub-cellular localization of the identified proteins. In total, 93 different extracellular proteins of C. pseudotuberculosis were identified with high confidence by this strategy; 44 proteins were commonly identified in two different strains, isolated from distinct hosts, then composing a core C. pseudotuberculosis exoproteome. Analysis with the SurfG+ tool showed that more than 75% (70/93) of the identified proteins could be predicted as containing signals for active exportation. Moreover, evidence could be found for probable non-classical export of most of the remaining proteins. Conclusions: Comparative analyses of the exoproteomes of two C. pseudotuberculosis strains, in addition to comparison with other experimentally determined corynebacterial exoproteomes, were helpful to gain novel insights into the contribution of the exported proteins in the virulence of this bacterium. The results presented here compose the most comprehensive coverage of the exoproteome of a corynebacterial species so far

Study of the Technical Feasibility of the Use of Polypropylene Residue in Composites for Automotive Industry

Polypropylene (PP) is widely used in short-term use artifacts, rapidly discarded and should partially replace neat PP. In addition, it is one of the polymers most used in the automobile industry. This study shows the technical feasibility of partially substituting neat PP for a post-consumer counterpart (PPr), as well as adding ground glass (GP), used as filler in the polymer matrix. Mechanical and thermal properties of the recycled blends (PP/PPr) and composites (PP/PPr/GP) were evaluated. The results demonstrated that the blend with the highest PPr content obtained a statistically significant decline in elastic modulus, but adding 5 wt% of GP to this blend increased this property, achieving a similar value in relation to neat PP. The composite developed may be a promising tailor-made product with properties resembling those of the virgin plastic. Thus, the automotive industry seems to be a good option for the use of PPr and GP composites and blends, without increasing product requirements

Analysis of prion protein gene (prnp) polymorphisms in healthy Morada Nova sheep reveals the presence of genotypes susceptible to scrapie.

Prion diseases, such as sheep scrapie, are usually associated with certain genotypes of prion protein gene (PRNP). Polymorphisms at codons 136, 154 and 171 of ovine PRNP open reading frame (ORF) are believed to confer either resistance or susceptibility to scrapie. In this study 72 healthy sheep from two different flocks, representing two meat type color variants from hair breed Morada Nova, from the State of Ceará, Brazil, were analyzed. PRNP ORF sequences were investigated for single nucleotide polymorphisms (SNPs) detection, followed by genotype analysis of codons 136, 154 and 171. Well known polymorphisms at codons 136 (coding for A/V) and 171 (coding for Q/R) were identified among the subjects, while at codon 154 only codon R has been observed. PRNP genotypes observed among Morada Nova subjects were ARQ/ ARQ (34.75%), ARQ/ARR (30.49%), ARR/ARR (31.92%) and the rare VRR/VRR (2.78%). We suggest here that the observed high homozygote frequency among Morada Nova PRNP genotypes AA at codon 136 and RR at codon 171 could be a genetic element for a putative natural resistance to scrapie. This is the first report of PRNP genotyping in Morada Nova breed and the first time the scrapie susceptible allele VRR has been identified in Brazil. RESUMO - Doenças priônicas, como o scrapie (Paraplexia Enzoótica dos Ovinos) estão usualmente associadas com determinados genótipos do gene da proteína priônica (PRNP). Polimorfismos na matriz aberta de leitura (ORF) dos códons 136, 154 e 171 de PRNP de ovinos estão associados a resistência ou suscetibilidade a scrapie. Neste estudo, um total de 72 ovinos saudáveis, de 2 rebanhos e diferente variação de cor de pelagem, da raça deslanada Morada Nova no Estado do Ceará, foram analisadas. Seqüências PRNP, compreendendo as ORF, do gene PRNP foram investigadas para a identificação dos Polimorfismos de único nucleotídeo (SNPs), seguida de detalhado seqüenciamento do DNA e análise bioinformática para os códons 136, 154 e 171. As freqüências genotípicas dos polimorfismos do PRNP são relatadas. Os polimorfismos já identificados no códon 136 (codificando A/V), 171 (codificando Q/R), entretanto no códon 154 não houve variação (somente R). As variantes alélicas e genotípicas para o PRNP observadas entre os ovinos Morada Nova foram: ARQ/ARQ (34,75%), ARQ/ARR (30,49%), ARR/ARR (31,92%) além do genótipo raro VRR/VRR (2,78%). Além das variantes alélicas e genótipicas, nós discutimos a freqüência da homozigozidade dos alelos AA no códon 136 e RR no códon 171 do PRNP e correspondentes haplótipos nos ovinos Morada Nova como elementos genéticos como um suposto elemento de resistência natural a scrapie. Este é o primeiro relato de genotipagem para PRNP em ovinos da raça Morada Nova e primeira observação do genótipo VRR/VRR em rebanho brasileiro