Biocompatible Star Block Copolymer Hydrogel Cross-linked with Calcium Ions

Abstract

Hydrogels cross-linked with calcium ions (Ca 2+ ) have various potential medical applications. A star block copolymer with a dendritic polyester (DPE) core and double hydrophilic block copolymer arms composed of oligo(ethylene glycol) methyl ether acrylate (OEGA) and acrylic acid (AA) has been synthesized for the first time. This star block copolymer showed a spherical morphology with an average diameter of 62 nm and rapidly formed a hydrogel in normal saline under physiological conditions when it was mixed with Ca 2+ . Furthermore, the star block copolymer and its hydrogel cross-linked by Ca 2+ showed excellent biocompatibility both in vitro and in vivo.

Stimuli‐Responsive Polypeptide‐Based Supramolecular Hydrogels Mediated by Ca2+ Ion Cross‐Linking

“…The gelation behavior is reversible with temperature. It is evident that the complexation of the triblock copolymer with Ca 2+ ions results in the formation of hydrogel . Furthermore, the sol‐to‐gel transition temperature decreases largely with increasing salt concentration.…”

Calcium ion‐induced self‐healing pattern of chemically crosslinked poly(acrylic acid) hydrogels

“…Poly(acrylic acid) (PAA) is a hydrophilic and superabsorbent polymer which is frequently used in various applications, especially in drug delivery due to the presence of carboxyl groups which induce hydrophilicity, ionic character and pH responsiveness. Several studies have been reported regarding the use of PAA gels in self‐healing applications by exploiting the carboxyl functionality which mediates hydrogen bonding across a damaged hydrogel . PAA is an ionically crosslinkable hydrogel and it has been observed to form physical crosslinks with several multivalent ions .…”

“…Several studies have been reported regarding the use of PAA gels in self-healing applications by exploiting the carboxyl functionality which mediates hydrogen bonding across a damaged hydrogel. [18][19][20][21][22] PAA is an ionically crosslinkable hydrogel and it has been observed to form physical crosslinks with several multivalent ions. [19][20][21][22] However, PAA hydrogels do not undergo sufficient crosslinking with divalent ions, such as calcium and magnesium, and hence may be chemically crosslinked with additional crosslinkers to create double-crosslinked network structures.…”

“…[18][19][20][21][22] PAA is an ionically crosslinkable hydrogel and it has been observed to form physical crosslinks with several multivalent ions. [19][20][21][22] However, PAA hydrogels do not undergo sufficient crosslinking with divalent ions, such as calcium and magnesium, and hence may be chemically crosslinked with additional crosslinkers to create double-crosslinked network structures. 18 Wei and co-workers reported autonomous self-healing hydrogels based on both chemically and ionically crosslinked PAA chains where mobility of ferric ions (Fe 3+ ) was responsible for the self-healing of the hydrogels.…”

3D inkjet printing of star block copolymer hydrogels cross-linked using various metallic ions

“…We have previously reported a star block copolymer that can form a homogeneous hydrogel without polymer precipitation through mixing with calcium ion (Ca 2+ ) 20 or ferric ion (Fe 3+ ). 21 This star block copolymer has a dendritic polyester (DPE) core, a poly(oligo(ethylene glycol) methyl ether acrylate) (polyOEGA) inner layer, and a poly(acrylic acid) (PAA) outer layer (Fig.…”