Active Loading of Pectin Hydrogels for Targeted Drug Delivery

Abstract

Hydrogels provide a promising method for the targeted delivery of protein drugs. Loading the protein drug into the hydrogel free volume can be challenging due to limited quantities of the drug (e.g., growth factor) and complex physicochemical properties of the hydrogel. Here, we investigated both passive and active loading of the heteropolysaccharide hydrogel pectin. Passive loading of glass phase pectin films was evaluated by contact angles and fractional thickness of the pectin films. Four pectin sources demonstrated mean contact angles of 88° with water and 122° with pleural fluid (p < 0.05). Slow kinetics and evaporative losses precluded passive loading. In contrast, active loading of the translucent pectin films was evaluated with the colorimetric tracer methylene blue. Active loading parameters were systematically varied and recorded at 500 points/s. The distribution of the tracer was evaluated by image morphometry. Active loading of the tracer into the pectin films required the optimization of probe velocity, compression force, and contact time. We conclude that active loading using pectin-specific conditions is required for the efficient embedding of low viscosity liquids into pectin hydrogels.

Facilitated Transport across Glycocalyceal Barriers in the Chick Chorioallantoic Membrane

“…Facilitated diffusion . To facilitate tracer transport into the CAM, the tracers—at identical concentration and volumes—were actively loaded into pectin films [ 10 ]. Upon contact with the CAM surface, the pectin films became densely adherent.…”

“…Active loading is a technique used to embed a high concentration of a substance within the carrier system. Our approach to the active loading of the tracers into the polymer films has been described elsewhere [ 10 ]. Briefly, we used compression with a 25 mm diameter acrylic disk to embed the tracer into pectin films using a 5 kg load cell (TA-XT plus; Stable Micro Systems, Godalming, UK).…”

“…The most abundant component of pectin is homogalacturonan, a glycan of α1→4-linked D-galacturonic acid that can be largely carboxy methyl esterified. Relevant to drug delivery, pectin has a significant water (free) volume available for drug loading [ 10 ]. In addition, pectin films have a branched-chain structure that physically entangle with the glycocalyx on the epithelial surface [ 11 ].…”

Pectin hydrogels for controlled drug release: Recent developments and future prospects

“…This entrapment process involves the formation of a drug-loaded matrix, in which drug molecules are distributed within the hydrogel. Pectin hydrogels have garnered considerable attention in the development of drug delivery platforms that offer precise control over drug-release rates, ultimately enhancing the efficacy and safety of various therapeutic treatments ( Vesvoranan et al, 2022 ).…”

Biomechanics of a Plant-Derived Sealant for Corneal Injuries

“… 19 – 21 In traumatic injuries, the potential to embed drugs in the pectin “free volume” provides an additional opportunity for targeted drug delivery. 22 …”