Novel Poly(amido‐amine)‐Based Hydrogels as Scaffolds for Tissue Engineering

Abstract

Biodegradable and biocompatible amphoteric poly(amido-amine) (PAA)-based hydrogels, containing carboxyl groups along with amino groups in their repeating unit, were considered as scaffolds for tissue engineering applications. These hydrogels were obtained by co-polymerising 2,2-bisacrylamidoacetic acid with 2-methylpiperazine with or without the addition of different mono-acrylamides as modifiers, and in the presence of primary bis-amines as crosslinking agents. Hybrid PAA/albumin hydrogels were also prepared. The polymerisation reaction was a Michael-type polyaddition carried out in aqueous media. The PAA hydrogels were soft and swellable materials. Cytotoxicity tests were carried out by the direct contact method with fibroblast cell lines on the hydrogels both in their native state (that is, as free bases) and as salts with acids of different strength, namely hydrochloric, sulfuric, acetic and lactic acid. This was done in order to ascertain whether counterion-specific differences in cytotoxicity existed. It was found that all the amphoteric PAA hydrogels considered were cytobiocompatible both as free bases and salts. Selected hydrogels samples underwent degradation tests under controlled conditions simulating biological environments, i.e. Dulbecco medium at pH 7.4 and 37 degrees C. All samples degraded completely and dissolved within 10 d, with the exception of hybrid PAA/albumin hydrogels that did not dissolve even after eight months. The degradation products of all samples turned to be non-cytotoxic. All these results led us to conclude that PAA-based hydrogels have a definite potential as degradable matrices for biomedical applications.

Prevailingly Cationic Agmatine-Based Amphoteric Polyamidoamine as a Nontoxic, Nonhemolytic, and “Stealthlike” DNA Complexing Agent and Transfection Promoter

“…6 This may be ascribed to the absence of membrane interaction, as indirectly confirmed by the fact that ISA23 hydrogels are biocompatible, but exhibit antiadhesive properties toward the same cells that eagerly adhere and proliferate on AGMA1 hydrogels. 22 At pH 7.4, AGMA1 is definitely cationic, yet when injected it apparently behaves like the prevailingly anionic PAAs. We hypothesize that AGMA1 is able to localize on the blood cell membranes without destabilizing them, thus escaping clearance.…”

Micro- and Nanoscale Hydrogel Systems for Drug Delivery and Tissue Engineering

“…The pores within the network provide space for cells, and after proliferation and growth, for the newly regenerated tissue [155]. Ferruti and co-workers have prepared biodegradable, biocompatible amphoteric poly(amido-amine) (PAA)-based hydrogels containing carboxyl groups along with amino groups in their repeating unit, as scaffolds for tissue engineering applications [156]. They also synthesized hybrid PAA/albumin hydrogels.…”

Biodegradable polymers applied in tissue engineering research: a review

“…The method of fabrication made it possible to have side substituents with biomimicking properties, such as carboxyl, ter‐amino, hydroxyl, allyl, or bioactive molecules like proteins and peptides. In vitro assays performed by Ferruti et al 46 investigated cytotoxicity, compatibility, and proliferation of the materials and the cells in contact with them. Biological evaluation results exhibited non‐toxicity, comparable cell proliferation (more than 70%) to normal TCPS plates, and normal cell morphology.…”