A new strategy to reduce amyloid deposition using peptide-imprinted membranes.

BACKGROUND: The accumulation of amyloid beta protein in the brain causes the cognitive impairment observed in neurodegenerative pathologies such as Alzheimer's disease. The present study aimed to test the hypothesis that a rapid removal of amyloid beta protein peptides from the blood by an extracorporeal purification system could represent an alternative solution for the treatment of patients suffering from this neurodegenerative disease. METHODS: In this regard, we investigated the specific recognition properties of a molecularly imprinted membrane based on poly(ethylene-co-vinyl alcohol) toward the amyloid beta protein fragment 25-35 (AbP), the more neurotoxic domain of amyloid beta protein. A chemical modification of the copolymer backbone using succinic anhydride was also performed to favor the formation of carboxylic groups and thus improve imprinting performance. RESULTS: The physico-chemical, morphological, mechanical and functional characterisations gave interesting results confirming the ability of imprinted membranes to in vitro rebind AbP. CONCLUSIONS: This work represents a proof of concept regarding the development of a biocompatible polymer membrane capable of selectively removing amyloid beta peptide from the blood and consequently from the cerebrospinal fluid.

New acrylate terpolymer-based nanoparticles for the release of nucleic acid: a preliminary study.

PURPOSE: Nano-drug delivery systems based on polymeric biomaterials have received considerable interest as drug delivery vehicles. In this work, radical polymerization was carried out in order to obtain nanoparticles based on a new acrylate terpolymer (PBMA-(PEG)MEMA-PDMAEMA). METHODS: Nanoparticles were developed in the form both of nanospheres and nanocapsules, an innovative kind of hollow nanoparticles with a great potential because of their low effective density and high specific surface area. The ability of the nanoparticles to load and then release a nucleic acid (DNA) to be used in cancer treatment was also investigated. RESULTS: Scanning electron microscopy analysis showed a spherical shape, nanometric dimensions, and a homogeneous distribution of the nanoparticles, also confirmed by dynamic light scattering measurements. Fourier-transform infrared spectroscopy chemical imaging analysis carried out on the nanocapsules before and after removal of the core demonstrated the presence of the cavity. High-performance liquid chromatography analysis confirmed good encapsulation efficiency of DNA both for nanospheres and nanocapsules. Drug release tests showed controlled release kinetics for both the systems with a high release of DNA in the first hours. In vitro MTT assay showed that the particles do not have cytotoxic effects on the cells. CONCLUSIONS: The preliminary investigation showed that the terpolymer-based nanoparticles developed in this study could be good candidates to be used as innovative and versatile gene delivery systems.

Morpho-functional characterization of human mesenchymal stem cells from umbilical cord blood for potential uses in regenerative medicine.

Mesenchymal stem cells (MSCs) represent a promising source of progenitor cells having the potential to repair and to regenerate diseased or damaged skeletal tissues. Bone marrow (BM) has been the first source reported to contain MSCs. However, BM-derived cells are not always acceptable, due to the highly invasive drawing and the decline in MSC number and differentiative capability with increasing age. Human umbilical cord blood (UCB), obtainable by donation with a noninvasive method, has been introduced as an alternative source of MSCs. Here human UCB-derived MSCs isolation and morpho-functional characterization are reported. Human UCB-derived mononuclear cells, obtained by negative immunoselection, exhibited either an osteoclast-like or a mesenchymal-like phenotype. However, we were able to obtain homogeneous populations of MSCs that displayed a fibroblast-like morphology, expressed mesenchym-related antigens and showed differentiative capacities along osteoblastic and early chondroblastic lineages. Furthermore, this study is one among a few papers investigating human UCB-derived MSC growth and differentiation on three-dimensional scaffolds focusing on their potential applications in regenerative medicine and tissue engineering. UCB-derived MSCs were proved to grow on biodegradable microfiber meshes; additionally, they were able to differentiate toward mature osteoblasts when cultured inside human plasma clots, suggesting their potential application in orthopedic surgery.