Microgel particles: The structure‐property relationships and their biomedical applications

Abstract

Microgels are crosslinked soft particles with a threedimensional network structure that are swollen in a good solvent. They have frequently been termed "smart materials" since the size, softness, and interaction forces between particles are tunable by external stimuli such as temperature, pH, or magnetic and electric fields. It is this unique feature that has captured the interest of many scientists across a wide range of disciplines. This brief review covers the basic aspects of the relationships between the network structure and gel properties of the thermally sensitive poly(N-isopropylacrylamide) (pNIPAM) microgels including the phase transition process, the internal structure of microgels, and the phase behavior. Additionally, we highlight the impacts of microgels on the biomedical applications, especially in the gene delivery, cell matrix and differentiation of stem cells.Recently, new applications for microgels have emerged most notably in stem cell research, tissue engineering, and in vitro diagnostics. 12,29,30 These practical applications not only require mechanical and chemical versatility from microgels, but also they require cell compatibility based on the In the memory of the late Professor Zhibing

Poly(N-isopropyl acrylamide)-block-poly(n-butyl acrylate) thermoresponsive amphiphilic copolymers: Synthesis, characterization and self-assembly behavior in aqueous solutions

“…The structure of PNIPAM containing both hydrophilic (amide) and hydrophobic (isopropyl) group makes this polymer an important model system for studying cold denaturation of proteins [5]. Since the lower critical solution temperature (LCST) of PNIPAm in water, 305 K, is close to the body temperature, PNIPAm was proposed as a component of various thermoresponsive drug delivery systems [6,7].…”

Microgel Mechanics in Biomaterial Design

“…16,17 Microgels are similar to hydrogels in that they comprise a solvent swollen polymer network. However, microgels are colloidal particles with dimensions ranging from tens of nanometers to many micrometers, enabling their interfacing with cellular and subcellular domains.…”

Mechanically Defined Microgels by Droplet Microfluidics

“…Furthermore, stimuli‐responsive hydrogel materials permit control over swelling by applying external stimuli, including temperature, pH, light, or ionic strength . This is utilized to encapsulate, for instance, biomolecules in the collapsed state for subsequent release in the swollen state . In addition, swelling and collapsing of the gel network significantly affects the elastic modulus of hydrogels, often simplified as stiffness .…”