Polymeric Particulates of Controlled Rigidity for Biomedical Applications

Abstract

The mechanical stiffness of polymer particles is an important parameter that influences particle circulation in the blood and governs cell–particle adhesion, cellular uptake, and biodistribution. This Review highlights the main approaches to produce micro and nanosized polymeric particulates with controlled mechanical responses and their applications in the biomedical field. We discuss how varying mechanical properties of polymeric particles can affect particle interactions with various types of cancer and immune cells, along with particle behavior in the flow. We also analyze the possibilities of regulating particle rigidity by controlling particle shape, a relatively unexplored research area. The main measurement methods to test the mechanical responses of polymeric particulates are also reviewed. Finally, we summarize recent developments toward controlling the mechanical responses of polymeric particulates relevant to biomedical applications and highlight important perspective directions that can advance fundamental and applied research in this area.

Resolving the different bulk moduli within individual soft nanogels using small-angle neutron scattering

“…Soft and compressible colloids are often the building blocks of many of the systems used in soft matter. Due to their softness, an increase in concentration, which consequently increases the suspension osmotic pressure, π, causes the particles to either change their volume by isotropically shrinking ( 1 – 3 ) or change their shape by faceting ( 3 – 6 ). To disentangle these effects, it is crucial to know the particle bulk modulus, K=−vnormal∂normalπnormal∂v, which quantifies the resistance of the material to isotropically changing its volume.…”

Controlling Mechanical Properties of Poly(methacrylic acid) Multilayer Hydrogels via Hydrogel Internal Architecture

“…Controlling hydrogel mechanical properties is essential for regulating tissue growth, cell adhesion, gene expression, and fabricating effective, flexible sensors. − Manipulating hydrogel cross-link density, polymer content, and chemical composition has been a main approach to adjusting hydrogel rigidity. − In addition, varying hydrogel microporosity via solvent casting/particle leaching, electrospinning, freeze-drying, and gas foaming has been shown to affect stiffness, swelling, and solute transport in bulk hydrogels. ,− For example, reducing hydrogel porosity by increasing the concentration of alginate in methacrylated gelatin resulted in a stiffer and more compact alginate-based hydrogel …”

“…Thickness (d), the Number of D 2 O Molecules Associated with Each Monomer in the Swollen Hydrogel (n w ), the Number of D 2 O Molecules per Unit of Volume (N w ), Swelling Ratio (SR), and Density (ρ) of (40-PMAA) 20 and (280-PMAA)20 Hydrogels Obtained from NR Data Supporting Information). Thus, at pH 5.05, n w values of 8.2 ± 0.1 and 9.6 ± 0.2 were found for (40-PMAA) 20 and (280-PMAA) 20 , respectively (Table1) with a similar trend at pH 6.55 with the n w values increasing to 9.8 ± 0.1 and 12.2 ± 0.2 for (40-PMAA) 20 and (280-PMAA) 20 , respectively (Table1).…”

Structure–function relationships in polymeric multilayer capsules designed for cancer drug delivery

“…The technologies of the synthesis of multilayer structures and methods of their encapsulation are rapidly improving and allow designing versatile stimulussensitive targeted systems serving as anticancer therapeutic tools. Recent reviews are mainly focused on the designing and functionalization of capsule-based delivery tools consisting of metal nanoparticles, drugs, and vector molecules [64][65][66] . However, the issues of capsule design, their targeted delivery to cancer cells, and their biointeractions are still rarely discussed 67 .…”

“…Recent reviews are mainly focused on the design and functionalization of capsule-based delivery tools consisting of metal nanoparticles, drugs, and vector molecules. [64][65][66] However, the issues of capsule design, their targeted delivery to cancer cells, and their biointeractions are still rarely discussed. 67 Therefore, a comprehensive systematic analysis of the influence of the multilayer capsule design on both opsonization of the capsules and their interaction with blood constituents and cancer cells is called for.…”