Search results for "Microgels"
showing 8 items of 8 documents
Rational Design of Thermoresponsive Microgel Templates with Polydopamine Surface Coating for Microtissue Applications.
2021
Functional microgels provide a versatile basis for synthetic in vitro platforms as alternatives to animal experiments. The tuning of the physical, chemical, and biological properties of synthetic microgels can be achieved by blending suitable polymers and formulating them such to reflect the heterogenous and complex nature of biological tissues. Based on this premise, this paper introduces the development of volume-switchable core-shell microgels as 3D templates to enable cell growth for microtissue applications, using a systematic approach to tune the microgel properties based on a deep conceptual and practical understanding. Microscopic microgel design, such as the tailoring of the microg…
Bone Scaffolds Based on Degradable Vaterite/PEG‐Composite Microgels
2019
Vaterite, a metastable modification of calcium carbonate, embedded in a flexible microgel packaging with adjustable mechanical properties, functionality, and biocompatibility, provides a powerful scaffolding for bone tissue regeneration, as it is easily convertible to bone-like hydroxyapatite (HA). In this study, the synthesis and physical analysis of a packaging material to encapsulate vaterite particles and osteoblast cells into monodisperse, sub-millimeter-sized microgels, is described whereby a systematic approach is used to tailor the microgel properties. The size and shape of the microgels is controlled via droplet-based microfluidics. Key requirements for the polymer system, such as …
Functionalized Poly(N-isopropylacrylamide)-Based Microgels in Tumor Targeting and Drug Delivery
2021
Over the past several decades, the development of engineered small particles as targeted and drug delivery systems (TDDS) has received great attention thanks to the possibility to overcome the limitations of classical cancer chemotherapy, including targeting incapability, nonspecific action and, consequently, systemic toxicity. Thus, this research aims at using a novel design of Poly(N-isopropylacrylamide) p(NIPAM)-based microgels to specifically target cancer cells and avoid the healthy ones, which is expected to decrease or eliminate the side effects of chemotherapeutic drugs. Smart NIPAM-based microgels were functionalized with acrylic acid and coupled to folic acid (FA), targeting the f…
Injectable in situ forming microgels of hyaluronic acid-g-polylactic acid for methylprednisolone release
2013
Abstract A hydrophobic derivative of hyaluronic acid (HA), obtained by grafting polylactic acid (PLA) to the polysaccharide, has been exploited to produce injectable in situ forming microgels. First of all, self assembling properties of HA-g-PLA copolymer have been evaluated by determining the critical aggregation concentration (CAC) value, then this copolymer has been dissolved in a mixture water/NMP 5:2 v/v with a concentration greater than CAC. When solutions at 1% or 2% w/v were injected into Dulbecco phosphate buffer solution (DPBS) pH 7.4, microgels promptly are formed. Their stability in DPBS pH 7.4 in the absence or in the presence of hyaluronidase and cell compatibility have been e…
On the nature of macroradicals formed upon radiolysis of aqueous poly(N-vinylpyrrolidone) solutions
2020
In this work we have explored the nature of macroradicals formed upon radiolysis of aqueous poly(N-vinylpyrrolidone) (PVP) solutions using pulse radiolysis, density functional theory (DFT) and literature data. On the basis of literature data on site-specific kinetics of hydrogen abstraction from simple amides and spectra corresponding to specific radical sites on the same amides we have assessed the distribution of H-atom abstraction by `OH radicals from different positions on the pyrrolidone ring and the polymer backbone. Pulse radiolysis experiments performed at different doses per pulse and different PVP concentrations demonstrate that the H-abstracting radiolysis products are not quanti…
Chemically Fueled Volume Phase Transition of Polyacid Microgels
2021
Abstract Microgels are soft colloids that show responsive behavior and are easy to functionalize for applications. They are considered key components for future smart colloidal material systems. However, so far microgel systems have almost exclusively been studied in classical responsive switching settings using external triggers, while internally organized, autonomous control mechanisms as found in supramolecular chemistry and DNA nanotechnology relying on fuel‐driven out‐of‐equilibrium concepts have not been implemented into microgel systems. Here, we introduce chemically fueled transient volume phase transitions (VPTs) for poly(methacrylic acid) (PMAA) microgels, where the collapsed hydr…
Radiation engineered nanogels as platforms for medical diagnostics and therapeutic nanodevices
2015
A scalable, single step, synthetic approach for the manufacture of biocompatible, functionalized microgels and nanogels has been developed. Pulsed EB irradiation of PVP aqueous solutions, at relatively low energies per pulse and doses within the sterilization dose range, has led to a variety of ‘as-born’ sterile, functional nanostructures that exhibit a combination of favourable properties which make them suitable as biomedical nanocarriers. Reactive functional groups have been generated by graft copolymerization of functional acrylic monomers. These groups can be used to attach fluorescent probes to the NPs, to bioconjugate ligands of specific cell receptors and to incorporate therapeutics…
Synthesis of Biocompatible and Biodegradable Polyamidoamines Microgels via a Simple and Reliable Statistical Approach.
2022
Polyamidoamines (PAAs) are biocompatible and biodegradable polymers with a huge potential as biomaterials for pharmaceutical applications. They are obtained by the step-wise aza-Michael polyaddition of bifunctional or multifunctional amines with bisacrylamides in water. To the best of our knowledge, no synthetic protocols leading to hyperbranched PAAs as well as PAA microgels have been published so far. To fill this gap, a statistical approach was established in this work to fine-tune the aza-Michael polyaddition stoichiometry when a multifunctional co-monomer (bf) is added to a mixture of bifunctional monomers with complementary functions (a2 + b2), possibly even in presence of a monofunct…