Mechanistic insights into the calcium-mediated gelation of poly(4--butylstyrene--maleic acid)--poly(-acryloylmorpholine) double hydrophilic block copolymers
Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine
Stimuli responsive double hydrophilic block copolymers (DHBCs) are ubiquitous in water-based applications, such as drug/gene delivery, nanoreactor and sensor development, photocatalysis, 3D inkjet printing, etc. DHBC-based gels, cross-linked with calcium ions, are particularly valuable for the development of biomedically relevant materials (such as wound dressings or injectable formulations), due to the benignity of Cain biological systems. Therefore, gels formedthe calcium-mediated crosslinking of poly(4--butylstyrene--maleic acid)--poly(-acryloylmorpholine) (PBuSMA--PNAM), which in itself constitutes polymers with established biomedical relevance, are promising candidates for the development of the aforementioned biomedical materials. To this end, PBuSMA--PNAM diblock copolymers were synthesized with different block ratios (1:1, 1:2 and 2:1) and treated with Ca, whereby the concentration of the two constituents, the pH or the block copolymer architecture was varied, in order to tune the mechanical properties of the PBuSMA--PNAM/Cagels. PBuSMA--PNAM/Cawith the lowest PBuSMA composition (1:2 block ratio) could not form gels and rather formed micelles, whereas PBuSMA--PNAM/Cawith the highest PBuSMA composition (2:1 block ratio) exhibited enhanced mechanical properties compared to the 1:1 block ratio. The overall amphiphilic balance of the PBuSMA--PNAM/Cacomplexes was therefore proven vital for the design and formation of gels with desirable mechanical properties. PBuSMA--PNAM/
Abstract
Stimuli responsive double hydrophilic block copolymers (DHBCs) are ubiquitous in water-based applications, such as drug/gene delivery, nanoreactor and sensor development, photocatalysis, 3D inkjet printing, etc. DHBC-based gels, cross-linked with calcium ions, are particularly valuable for the development of biomedically relevant materials (such as wound dressings or injectable formulations), due to the benignity of Cain biological systems. Therefore, gels formedthe calcium-mediated crosslinking of poly(4--butylstyrene--maleic acid)--poly(-acryloylmorpholine) (PBuSMA--PNAM), which in itself constitutes polymers with established biomedical relevance, are promising candidates for the development of the aforementioned biomedical materials. To this end, PBuSMA--PNAM diblock copolymers were synthesized with different block ratios (1:1, 1:2 and 2:1) and treated with Ca, whereby the concentration of the two constituents, the pH or the block copolymer architecture was varied, in order to tune the mechanical properties of the PBuSMA--PNAM/Cagels. PBuSMA--PNAM/Cawith the lowest PBuSMA composition (1:2 block ratio) could not form gels and rather formed micelles, whereas PBuSMA--PNAM/Cawith the highest PBuSMA composition (2:1 block ratio) exhibited enhanced mechanical properties compared to the 1:1 block ratio. The overall amphiphilic balance of the PBuSMA--PNAM/Cacomplexes was therefore proven vital for the design and formation of gels with desirable mechanical properties. PBuSMA--PNAM/Cagels exhibited shear thinning when subjected to high shear conditions and demonstrated some self-healing properties, suggesting these materials have value in the formulation of injectable gels.