Poly(2-isopropenyl-2-oxazoline) Hydrogels for Biomedical Applications

Abstract

Synthetic polymers have had a major impact on the biomedical field. However, all polymers have their advantages and disadvantages, so that the selection of a certain polymeric material always is a compromise with regard to many properties, such as synthetic accessibility, solubility, thermal properties, biocompatibility and degradability. The development of novel polymers with superior properties for medical applications is the focus of many research groups. The present study highlights the use of poly(2-isopropenyl-2-oxazoline) (PiPOx), as biocompatible functional polymer to develop synthetic hydrogel materials using a simple straightforward synthesis protocol. A library of hydrogels was obtained by chemical cross-linking of PiPOx, using eight different non-toxic and bio-based dicarboxylic acids. The equilibrium swelling degree (ESD) of the final material can be modulated by simple modification of the composition of the reaction mixture, including the polymer concentration in the feed ratio between the 2-oxazoline pendent groups and the carboxylic acid groups as well as the cross-linker 2 length. The hydrogels with the highest water uptake were selected for further investigations regarding their potential use as biomaterials. We evaluated the thermoresponsiveness, the pH-degradability under physiological conditions and demonstrated proof-of-concept drug delivery experiments. The in vitro cellular studies demonstrated the noncytotoxic character of the PiPOx hydrogels, and its protein repellent properties, while mineralization studies revealed that such scaffolds do not promote mineralization/calcification phenomena. In view, of these results, these hydrogels show potential use as ophthalmologic materials or in drug delivery applications.

Improving Printability of a Thermoresponsive Hydrogel Biomaterial Ink by Nanoclay Addition

“…[29][30][31][32][33] In the last few years, especially chemically crosslinked POx-based hydrogels have been heavily investigated. 30,[33][34][35][36] More recently, a few different POx-based block copolymers that undergo thermogelation were described. For example, a diblock copolymer comprising a hydrophilic poly(2-methyl-2-oxazoline) (PMeOx) block and a thermoresponsive poly(2-n-propyl-2-oxazine) (PnPrOzi) block was described and used for bioprinting.…”

Synthesis and Investigation of Thermo-Induced Gelation of Partially Cross-Linked Poly-2-isopropyl-2-oxazoline in Aqueous Media

“…Briefly, the mixture of adipodinitrile (11 g, 0.1 mol), 2-aminoethanol (13.5 g, 0.22 mol), and Cd(OCOCH 3 ) 2 (2.3 g, 0.01 mol) was heated at 140 • C for 24 h. The target product was distilled, dried over sodium and redistilled. The yield was 10. multifunctional cross-linker [17][18][19][20] and oligo-and polyoxazoline chain cross-linking [21][22][23][24][25][26]. The hydrogels described in literature are characterized by high affinities for water and swelling degrees.…”

“…Polyoxazoline-based gels have great prospects to be used in biomedical applications due to the nontoxicity and biocompatibility of these polymers [9,15,16]. In general, there are two routes to cross-linked polyoxazoline production, which are the simultaneous copolymerization of monomers with a multifunctional cross-linker [17][18][19][20] and oligo-and polyoxazoline chain cross-linking [21][22][23][24][25][26]. The hydrogels described in literature are characterized by high affinities for water and swelling degrees.…”

Enhancement of Biomimetic Enzymatic Mineralization of Gellan Gum Polysaccharide Hydrogels by Plant-Derived Gallotannins

“…The mineralization of synthetic and natural hydrogels has been studied [7][8][9][10][11]. Synthetic hydrogels generally have better defined chemical structures, but often lack the functional groups with natural affinity for calcium (or phosphate) ions shown by natural polymers, such as alginate and GG.…”