Drug-Loaded Halloysite Nanotube-Reinforced Electrospun Alginate-Based Nanofibrous Scaffolds with Sustained Antimicrobial Protection

Abstract

Halloysite nanotube (HNT)-reinforced alginate-based nanofibrous scaffolds were successfully fabricated by electrospinning to mimic the natural extracellular matrix (ECM) structure which is beneficial for tissue regeneration. An antiseptic drug, cephalexin (CEF)-loaded HNT, was incorporated into the alginate-based matrix to obtain sustained antimicrobial protection and robust mechanical properties, the key criteria for tissue engineering applications. Electron microscopic imaging and drug release studies revealed that CEF had penetrated into the lumen space of the HNT and also deposited on the outer walls, with a total loading capacity of 30 wt %. Moreover, the diameter of alginate-based nanofibers of the scaffolds ranged from 40 to 522 nm with well-aligned HNTs, resulting in superior mechanical properties. For instance, the addition of 5% (w/w) HNT improved the tensile strength (σ) and elastic modulus by 3-fold and 2-fold, respectively, compared to those of the alginate-based scaffolds without HNT. The fabricated scaffolds exhibited remarkable antimicrobial properties against both Gram-negative and Gram-positive bacteria, and the cytotoxicity studies confirmed the nontoxicity of the fabricated scaffolds. Drug release kinetics showed that CEF inside HNTs diffuses within 24 h and that the diffusion of the drug is delayed by 7 days once the CEF-loaded HNTs are incorporated into the alginate-based nanofibers. These fabricated alginate-based electrospun scaffolds with enhanced mechanical properties and sustained antimicrobial protection hold great potential to be used as artificial ECM scaffolds for tissue engineering applications.

Aligned electrospun cellulose scaffolds coated with rhBMP-2 for both in vitro and in vivo bone tissue engineering

“…Collecting the fibers at a lower rotation speed (50 m/min) resulted in random nanofibers, whereas an irregular nonwoven architecture was revealed in the random sample (Figure 2.c), In contrast, a faster rotation speed of the collector (300 m/min) resulted in stretching of the fibers in the rotating direction of the collector, which gave highly oriented and ordered distribution of individual fibers (Figure 2.d). This finding was consistent with previous studies (De Silva et al, 2018;He et al, 2014;Im, Jung, Jang & Kim, 2016).…”

Electrospun Alginate Nanofibers Toward Various Applications: A Review

“…In another study, Jeong et al [73] electrospun a polyionic complex of alginate and chitosan in order to realize cell attachment and proliferation. An increase in chitosan content decreased the swelling ratio in deionized medium and the seeded mouse preosteoblast cells (MC3T3s) were found to adhere to the chitosan-alginate nanofibrous membrane and exhibited substantial proliferation from 5 to 120 h. The incorporation of nanoparticles into alginate nanofibrous membrane resulted in the enhancement of the mechanical properties and usefulness as multifunctional materials for tissue engineering applications [29,33,61,74]. Antiseptic (cephalexin (CEF))-loaded halloysite nanotubes (HNTs) were incorporated into an alginate-based nanofibrous membrane by mixing the HNT-loaded particles in an alginate/PVA solution, followed by electrospinning [74].…”

“…In order to overcome these challenges, these therapeutic genes are often immobilized on the biomaterial-based substrate. This kind of process promotes delivery efficiency on the targeted sites without systemic Reprinted with permission from [74]. HNT: halloysite nanotubes and CEF: cephalexin.…”

“…Antimicrobial activity of alginate-based scaffolds with 10% (w/w) cephalexin (CEF)-HNT. Reprinted with permission from[74]. HNT: halloysite nanotubes and CEF: cephalexin.…”

Natural clay-supported palladium catalysts for methane oxidation reaction: effect of alloying

“…Al-OH groups are present in the inner surface and Si-O groups dangle along the outer surface, which are inherent anchoring sites for various types of materials including polymers, drugs, metal oxides and metal nanoparticles. [37][38][39][40] Despite the promising properties of halloysite as a potential host for different types of materials, its use as a support for heterogeneous catalysis is still rare [41][42][43] and has not been reported for the methane oxidation reaction.…”