Supramolecular Guest–Host Interactions for the Preparation of Biomedical Materials

Abstract

Supramolecular chemistry has emerged as an important technique for the formation of biomaterials, including nano- and microparticles and hydrogels. One specific class of supramolecular chemistry is the direct association of guest-host pairs, which involves host macrocycles such as cyclodextrins and cucurbit[n]urils and a wide range of guest molecules, where association is typically driven by molecule size and hydrophobicity. These systems are of particular interest in the biomedical field due to their dynamic nature, chemical diversity, relative ease of synthesis, and ability to interact with biological or synthetic molecules. In this review, we discuss aspects of polymeric material assembly mediated by guest-host interactions, including the fundamentals of assembly into functional biomedical materials. Additionally, applications of biomaterials that utilize guest-host interactions are discussed with a focus on injectable material formulations, the sequestration and delivery of encapsulated cargo (i.e., drugs, biomolecules), and the investigation of cell-material interactions (i.e., adhesion, differentiation, and delivery). While methodologies for guest-host mediated assembly and biological interaction have rapidly evolved in recent years, they remain far from realizing their full potential in the biomaterials field.

Injectable Shear-Thinning Hydrogels for Minimally Invasive Delivery to Infarcted Myocardium to Limit Left Ventricular Remodeling

“…S5A). GH hydrogels are known to exhibit shear-thinning (during injection) and self-healing (after injection) properties 18 , 22 necessary for delivery into myocardial tissue (Fig. 1D); yet, shear-yielding was not observed at physiological myocardial strains (Fig.…”

Evolution of hierarchical porous structures in supramolecular guest–host hydrogels

“…18 Here, we utilized hyaluronic acid (HA) modified (Fig. 1A) by 1-adamantane acetic acid (Ad-HA) and aminated β-cyclodextrin (CD-HA) as previously described.…”

“…Due to the influence of macromolecular dynamics on the observed porosity, it is notable that the feature size and evolution timescale may also be drastically altered through selection of the supramolecular binding pairs, as the timescale for the transient associations is related to the equilibrium association constant (K eq ) which varies by greater than ten orders of magnitude. 18, 45 …”

“…16-18 Prominent among these physical hydrogels is the utilization of cyclodextrins, cucurbit[n]urils, and other host macrocycles that form dynamic physical associations with an array of corresponding guest molecules. 18, 19 Through polymer conjugation, these macrocycles have bridged the gap between simple supramolecular bonding and complex macromolecular self-assembly processes, enabling formation of precise nano- and micro-particulates, as well as bulk hydrogels.…”

Use of Polysaccharide Hydrogels in Drug Delivery and Tissue Engineering

“…These systems are dynamic, show chemical diversity, relative ease of synthesis, and show better ability to interact with biological or synthetic molecules. 30 An injectable chitosan based hydrogel is used for the treatment of Chronic rhinosinusitis. A small interfering RNA (siRNA) targeting VEGF was used to silence the expression of VEGF, loaded in gel for injection into the sinus cavity.…”