Human umbilical cord stem cell encapsulation in novel macroporous and injectable fibrin for muscle tissue engineering

Abstract

There has been little research on the seeding of human umbilical cord mesenchymal stem cells (hUCMSCs) in three-dimensional scaffolds for muscle tissue engineering. The objectives of this study were: (i) to seed hUCMSCs in a fibrin hydrogel containing fast-degradable microbeads (dMBs) to create macropores to enhance cell viability; and (ii) to investigate the encapsulated cell proliferation and myogenic differentiation for muscle tissue engineering. Mass fractions of 0–80% of dMBs were tested, and 35% of dMBs in fibrin was shown to avoid fibrin shrinkage while creating macropores and promoting cell viability. This construct was referred to as “dMB35”. Fibrin without dMBs was termed “dMB0”. Microbead degradation created macropores in fibrin and improved cell viability. The percentage of live cells in dMB35 reached 91% at 16 days, higher than the 81% in dMB0 (p < 0.05). Live cell density in dMB35 was 1.6-fold that of dMB0 (p < 0.05). The encapsulated hUCMSCs proliferated, increasing the cell density by 2.6 times in dMB35 from 1 to 16 days. MTT activity for dMB35 was substantially higher than that for dMB0 at 16 days (p < 0.05). hUCMSCs in dMB35 had high gene expressions of myotube markers of myosin heavy chain 1 (MYH1) and alpha-actinin 3 (ACTN3). Elongated, multinucleated cells were formed with positive staining of myogenic specific proteins including myogenin, MYH, ACTN and actin alpha 1. Moreover, a significant increase in cell fusion was detected with myogenic induction. In conclusion, hUCMSCs were encapsulated in fibrin with degradable microbeads for the first time, achieving greatly enhanced cell viability and successful myogenic differentiation with formation of multinucleated myotubes. The injectable and macroporous fibrin–dMB–hUCMSC construct may be promising for muscle tissue engineering applications.

Core–shell designed scaffolds for drug delivery and tissue engineering

“…Alginate is thus among the most commonly used polymers for the shell as it can crosslink easily in divalent solution while maintaining the hydrogel shape [25,26]. On the other hand, many cell compatible hydrogels can be used for the core including collagen, hyaluronic acid, and fibrin [26][27][28].…”

Natural polymers for the microencapsulation of cells

“…This particular approach has found many applications in tissue engineering, specifically for cell therapies to enhance cell retention after transplant. There are many examples in the literature of these injectable systems not only for restoring the myocardium after myocardial infarction [188][189][190] but also for other applications such as bone [191] or muscle regeneration [36].…”

Hydrogel biomaterials and their therapeutic potential for muscle injuries and muscular dystrophies

“…Fibrin has many inherent properties that confer an advantage for tissue repair in hydrogels used for skeletal muscle tissue regeneration strategies. This material has also been shown to increase the therapeutic efficacy of treatments for skeletal muscle disorders [29,32]. It has been reported already over a decade ago that exploiting fibrin gels for the delivery of primary myoblasts into rat gracilis skeletal muscle facilitates the integration of donor cells into host muscle fibres in a localized and time-dependent manner [69].…”

“…Fibrin hydrogels were incorporated with beads formed by gelation of gelatin and subsequent dissolution to form micrometre-sized pores. Human umbilical cord mesenchymal stem cells (hUCMSCs), which were encapsulated in this macroporous fibrin-microbead constructs, showed improved viability and myogenic differentiation [29].…”

“…Hydrogels have been employed, for example, as encapsulating cell delivery vehicles that are instructive in promoting either differentiation or maturation of skeletal muscle cells. Hydrogels have been designed to promote muscle cell integration concurrently with protecting the grafted cells from an environment characterized by chronic inflammation exacerbated by the transplantation procedure [29][30][31][32]. Among the types of hydrogels available, biocompatible and bioresorbable hydrogels are more commonly investigated, as they can be easily translated into clinical practice.…”