Technologie bioresorbowalnych wyrobów medycznych – opracowane w wyniku realizacji projektu kluczowego „Biodegradowalne wyroby włókniste”

Pod koniec 2008 r. rozpoczęto realizację projektu kluczowego pt. „Biodegradowalne wyroby włókniste”, POIG 01.03.01–00– 007/08 o akronimie BIOGRATEX. Projekt jest współfinansowany z funduszy strukturalnych w ramach Programu Operacyjnego Innowacyjna Gospodarka. Celem głównym projektu jest opracowanie innowacyjnych rozwiązań technologicznych, niezbędnych dla poszerzenia oferty wyrobów włóknistych produkowanych z użyciem polimerów biodegradowalnych, w większości pozyskiwanych z surowców odnawialnych, kierowanych nie tylko do sektora włókienniczego, ale również dla rolnictwa i medycyny. Celem niniejszej publikacji jest przedstawienie opisu trzech technologii odnoszących się do wyrobów przeznaczonych do zastosowań w medycynie regeneracyjnej. Opisano technologię formowania włókien z roztworu polimeru będącego kopolimerem L-laktydu i glikolidu (PGLA), którego syntezę opracowano w ramach projektu. Kolejna technologia dotyczy materiałów nanowłóknistych wytwarzanych metodą elektroprzędzenia z roztworu polimeru PGLA oraz z roztworu mieszaniny polimerów PGLA i hydroksymaślanu (PHB). Oba roztwory polimeru w DMSO przędziono z dodatkiem hydroksyapatytu (HAp). Wytworzony materiał włóknisty zaprojektowano do stosowania przy regeneracji tkanki kostnej, jako materiał osteokonduktywny, osteoinduktywny i bioresorbowalny. Trzecia opisana technologia odnosi się do wytwarzania prototypów bioresorbowalnych protez naczyń krwionośnych z PGLA o średnicach poniżej 6 mm. Przedstawiono możliwość zastosowania techniki elektroprzędzenia ze stopu polimeru wraz z wprowadzeniem dodatkowego procesu stabilizacji termicznej do wytwarzania struktur 3D o małych średnicach

Fabrication of Plga/Hap and Plga/Phb/Hap Fibrous Nanocomposite Materials for Osseous Tissue Regeneration

The study presents the manufacturing of nanofibrous structures as osteoconductive, osteoinductive materials for osseous tissue regeneration. The fibrous structures were obtained by electrospinning of poly(l-lactide-coglicolide) (PLGA) with addition of hydroxyapatite (HAp) and of a blend of PLGA with polyhydroxybutyrate with HAp added. The polymers used in the experiment were synthesised by an innovative method with a zirconium catalyst. First, the optimal electrospinning process parameters were selected. For the characterisation of the obtained osseous tissue reconstruction materials, the physical, macroscopic, functional, mechanical and thermal properties as well as crystallinity index were studied. The study of the radiation sterilisation influence on average molar mass, thermal and mechanical properties was made in order to analyse the degradation effect

Transscleral Optical Phase Imaging of the Human Retina.

In-vivo observation of the human retina at the cellular level is crucial to detect the first signs of retinal diseases and properly treat them. Despite the phenomenal advances in adaptive optics (AO) systems, clinical imaging of many retinal cells is still elusive due to the low signal-to-noise ratio induced by transpupillary illumination. We present a transscleral optical phase imaging (TOPI) method, which relies on high-angle oblique illumination of the retina, combined with AO, to enhance cell contrast. Examination of eleven healthy volunteer eyes, without pupil dilation, shows the ability of this method to produce in-vivo images of retinal cells, from the retinal pigment epithelium to the nerve fibre layer. This method also allows the generation of high-resolution label-free ex-vivo phase images of flat-mounted retinas. The 4.4°x 4.4° field-of-view in-vivo images are recorded in less than 10 seconds, opening new avenues in the exploration of healthy and diseased retinas

Spectrofluorometric characteristics of fluorescent dissolved organic matter in a surface microlayer in the Southern Baltic coastal waters

This paper presents results of characterization of Dissolved Organic Matter (DOM) using fluorescence spectroscopy in the surface microlayers (SML) and subsurface layers (SS) in the Baltic Sea. Samples for spectroscopic measurements were collected during five research cruises in April/May and October 2013 and 2014 in a surface microlayer and a subsurface layer at a depth of 1 m along two transects from the river outlets to the open sea. The first transect was located from the Vistula River outlet to the Gdansk Deep and the second transect was located ´ from the Łeba River outlet to Słupsk Furrow. Results indicated that DOM fluorescence intensity in the SML is higher by 20% compared to the SS. The Humification Index, HIX values were lower in SML than SS by 13%. That indicates that SML is depleted in molecules with high molecular weight and higher aromaticy. The inverse relationship of fluorescence intensity of dominant peaks with salinity both in SML and SS suggests that FDOM variability is regulated mostly by terrestrial DOM input

Multimodal Highlighting of Structural Abnormalities in Diabetic Rat and Human Corneas.

PURPOSE: This study aimed to highlight structural corneal changes in a model of type 2 diabetes, using in vivo corneal confocal microscopy (CCM). The abnormalities were also characterized by transmission electron microscopy (TEM) and second harmonic generation (SHG) microscopy in rat and human corneas. METHODS: Goto-Kakizaki (GK) rats were observed at age 12 weeks (n = 3) and 1 year (n = 6), and compared to age-matched controls. After in vivo CCM examination, TEM and SHG microscopy were used to characterize the ultrastructure and the three-dimensional organization of the abnormalities. Human corneas from diabetic (n = 3) and nondiabetic (n = 3) patients were also included in the study. RESULTS: In the basal epithelium of GK rats, CCM revealed focal hyper-reflective areas, and histology showed proliferative cells with irregular basement membrane. In the anterior stroma, extracellular matrix modifications were detected by CCM and confirmed in histology. In the Descemet's membrane periphery of all the diabetic corneas, hyper-reflective deposits were highlighted using CCM and characterized as long-spacing collagen fibrils by TEM. SHG microscopy revealed these deposits with high contrast, allowing specific detection in diabetic human and rat corneas without preparation and characterization of their three-dimensional organization. CONCLUSION: Pathologic findings were observed early in the development of diabetes in GK rats. Similar abnormalities have been found in corneas from diabetic patients. TRANSLATIONAL RELEVANCE: This multidisciplinary study highlights diabetes-induced corneal abnormalities in an animal model, but also in diabetic donors. This could constitute a potential early marker for diagnosis of hyperglycemia-induced tissue changes

Nephropathy in Pparg-null mice highlights PPARγ systemic activities in metabolism and in the immune system.

Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-dependent transcription factor involved in many aspects of metabolism, immune response, and development. Total-body deletion of the two Pparg alleles provoked generalized lipoatrophy along with severe type 2 diabetes. Herein, we explore the appearance and development of structural and functional alterations of the kidney, comparing Pparg null-mice to their littermate controls (carrying Pparg floxed alleles). We show that renal hypertrophy and functional alterations with increased glucosuria and albuminuria are already present in 3 weeks-old Pparg null-mice. Renal insufficiency with decreased creatinine clearance progress at 7 weeks of age, with the advance of the type 2 diabetes. At 52 weeks of age, these alterations are accompanied by signs of fibrosis and mesangial expansion. More intriguingly, aged Pparg null-mice concomitantly present an anti-phospholipid syndrome (APS), characterized by the late appearance of microthrombi and a mesangioproliferative pattern of glomerular injury, associated with significant plasmatic levels of anti-β2- glycoprotein1 antibodies and renal deposition of IgG, IgM, and C3. Thus, in line with the role of PPARγ in metabolic homeostasis, Pparg null-mice first represent a potent model for studying the initiation and the development of diabetic nephropathy. Second, and in relation with the important PPARγ activity in inflammation and in immune system, these mice also highlight a new role for PPARγ signaling in the promotion of APS, a syndrome whose pathogenesis is poorly known and whose current treatment is limited to prevention of thrombosis events