Work

Tunable Encapsulation of Proteins within Charged Microgels

Year: 2011

Type: article

Abstract: The binding of cytochrome c to pH and thermoresponsive colloidal hydrogels was investigated using multiangle light scattering, measuring loading through changes in particle molar mass and root mean square radius. Loosely cross-linked microgels [composed of a random copolymer of N-isopropylacrylamide (NIPAm) and acrylic acid (AAc)] demonstrated a high loading capacity for protein. Encapsulation was dependent on both the charge characteristics of the network and the salinity of the medium. Under favorable binding conditions (neutral pH, low ionic strength), microgels containing the highest studied charge density (30 mol% AAc) were capable of encapsulating greater than 9.7 × 10(5) cytochrome c molecules per particle. Binding resulted in the formation of a polymer-protein complex and condensation of the polymer. Anionic microgels demonstrated a change in density ~20-fold in the presence of oppositely charged proteins. These studies of cytochrome c encapsulation represent a significant step towards direct measurement of encapsulation efficiency in complex media as we pursue responsive nanogels and microgels for the delivery of macromolecular therapeutic agents.

Source: Macromolecules

DOI: 10.1021/ma201365p

Authors: Michael H. Smith, L. Andrew Lyon

Institution: Georgia Institute of Technology

Language: English

Topic: Hydrogels: synthesis, properties, applications

Subfield: Molecular Medicine

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funder: National Institute of General Medical Sciences

Award: Microsphere-mediated differentiation of embryonic stem cells