Polyscitech (www.polyscitech.com) provides a variety
of polymers through our distribution with Sigma-Aldrich. Recently a publication
came out using PLGA-PEG-PLGA triblock (PolyVivo AK24, Aldrich # 764817) for
generating a photosensitive hydrogel network. Read more at: Ninh, Chi, Madeline
Cramer, and Christopher J. Bettinger. "Photoresponsive hydrogel networks
using melanin nanoparticle photothermal sensitizers." Biomaterials Science
(2014). http://pubs.rsc.org/en/content/articlelanding/2014/bm/c3bm60321k/unauth#!divAbstract
“ABSTRACT: Photoreconfigurable and
photodegradable polymeric networks have broad utility as functional
biomaterials for many applications in medicine and biotechnology. The vast
majority of these functional polymers are synthesized using chemical moieties
that may be cytotoxic in vivo. Materials synthesized from these substituents
also pose unknown risk upon implantation and thus will encounter significant
regulatory challenges prior to use in vivo. This work describes a strategy to
prepare photodegradable hydrogel networks that are composed of
well-characterized synthetic polymers and natural melanin pigments found within
the human body. Self-assembled networks of
poly(L-lactide-co-glycolide)-poly(ethylene glycol) ABA triblock copolymers are
doped with melanin nanoparticles to produce reconfigurable networks based on
photothermal phase transitions. Self-assembled hydrogel networks with melanin
nanoparticles exhibit a storage modulus ranging from 1.5 ± 0.6 kPa to 8.0 ± 7.5
kPa as measured by rheology. The rate of UV-induced photothermal heating was
non-monotonic and varied as a function of melanin nanoparticle loading. A
maximum steady state temperature increase of 20.5 ± 0.30 °C was measured.
Experimental heating rates were in close agreement with predictions based on attenuation
of light in melanins via photothermal absorption and Mie scattering. The
implications of melanin nanoparticles on hydrogel network formation and
light-induced disintegration were also characterized by rheology and dynamic
light scattering. Taken together, this class of photoreconfigurable hydrogels
represents a potential strategy for photodegradable polymers with increased
likelihood for clinical translation.”
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