title: Development and analysis of semi-interpenetrating polymer networks for brain injection in neurodegenerative disorders.
abstract: OBJECTIVE
  Our aim was to assess the use of injectable, biocompatible and resorbable, hydrogel-based tools for innovative therapies against brain-related neurodegenerative disorders like Alzheimer's (AD) and Parkinson's (PD) diseases.
  
  
  METHODS
  Two compositions of semi-interpenetrating polymer networks (semi-IPNs) based on collagen and poly(ethylene glycol) (PEG) were investigated. We examined their viscoelastic properties, flow behavior, functional injectability, as well as in vitro biocompatibility with SH-SY5Y human neuroblastoma cells and murine primary neurons. We also evaluated the in vivo biological performance after subcutaneous and brain injection in mice.
  
  
  RESULTS
  selected semi-IPNs showed a gel-like behavior and were injectable through a 30 G needle, with the maximum load ranging from 3.0 to 3.9 N. In vitro results showed that immortalized cells kept their proliferative potential and neurons maintained their viability after embedding in both materials, with better performances for the gel with the higher collagen content. For both semi-IPNs, after subcutaneous injection, the inflammatory response was negligible; after brain injection, the tissue did not show any signs of damage or degeneration.
  
  
  CONCLUSIONS
  The results suggest that the selected semi-IPNs not only represent a proper environment for cells, but also, once injected in vivo, do not induce damage/inflammation in the surrounding brain tissue. These findings represent a crucial starting point for the development of minimally invasive and injectable hydrogel-based tools for innovative drug/cell-based therapeutic strategies against AD, PD, or other severe brain-related neurodegenerative pathologies.</p>
authors: 1 Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano and Unità di Ricerca Consorzio INSTM, Politecnico di Milano, Milan - Italy.
authors: Marta
authors: M
authors: Tunesi
authors: Sara
authors: S
authors: Batelli
authors: Serena
authors: S
authors: Rodilossi
authors: Teresa
authors: T
authors: Russo
authors: Annalisa
authors: A
authors: Grimaldi
authors: Gianluigi
authors: G
authors: Forloni
authors: Luigi
authors: L
authors: Ambrosio
authors: Alberto
authors: A
authors: Cigada
authors: Antonio
authors: A
authors: Gloria
authors: Diego
authors: D
authors: Albani
authors: Carmen
authors: C
authors: Giordano
mesh_terms: D000180:Acrylic Resins; D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology; D001921:Brain; D003094:Collagen; D006801:Humans; D020100:Hydrogels; D019636:Neurodegenerative Diseases; D011092:Polyethylene Glycols; D011108:Polymers
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D020100:Hydrogels; D011108:Polymers; D011092:Polyethylene Glycols; D003094:Collagen