Compatibility of Cardiac Muscle Cells on Coated-Gelatin Electro-Spun Polyhydroxybutyrate/valerate Nano Fibrous Film

Progress in cardiac tissue engineering and regeneration: Implications of gelatin-based hybrid scaffolds

Cardiovascular diseases, particularly myocardial infarction (MI), remain a leading cause of morbidity and mortality worldwide. Current treatments for MI, more palliative than curative, have limitations in reversing the disease completely. Tissue engineering (TE) has emerged as a promising strategy to address this challenge and may lead to improved therapeutic approaches for MI. Gelatin-based scaffolds, including gelatin and its derivative, gelatin methacrylate (GelMA), have attracted significant attention in cardiac tissue engineering (CTE) due to their optimal physical and biochemical properties and capacity to mimic the native extracellular matrix (ECM). CTE mainly recruits two classes of gelatin/GelMA-based scaffolds: hydrogels and nanofibrous. This article reviews state-of-the-art gelatin/GelMA-based hybrid scaffolds currently applied for CTE and regenerative therapy. Hybrid scaffolds, fabricated by combining gelatin/GelMA hydrogel or nanofibrous scaffolds with other materials such as natural/synthetic polymers, nanoparticles, protein-based biomaterials, etc., are explored for enhanced cardiac tissue regeneration functionality. The engraftment of stem/cardiac cells, bioactive molecules, or drugs into these hybrid systems shows great promise in cardiac tissue repair and regeneration. Finally, the role of gelatin/GelMA scaffolds combined with the 3D bioprinting strategy in CTE will also be briefly highlighted.

Fabrication of polyhydroxybutyrate (PHB)/γ-Fe2O3 nanocomposite film and its properties study

Magnetic separation has numerous advantages in isolating cancerous and normal cells used in the diagnosis and treatment sectors. Here, we produced magnetic nanocomposite films made of polyhydroxybutyrate (PHB)/magnetite nanoparticles (γ-Fe2O3), and the properties of the films by SEM, TEM, FTIR, DMTA, contact angle, and cellular analyses were investigated. The microscopic images showed uniform distribution of γ-Fe2O3 magnetic nanoparticles in polymeric matrix. The chemical bounds between magnetic nanoparticles and polymeric matrix demonstrated using the FTIR spectrophotometer. The DMTA and contact angle results indicated an increase in the glass transition temperature and hydrophilic properties of nanocomposites is achieved by increasing the magnetic nanoparticles amount in polymer matrix. The cellular results were showed that adhesion of cancer cells compared to normal cells was significantly enhanced by the induction of a magnetic field. These nanocomposite films can be used as a substrate for cellular adhesion and separation processes.

Electrospun poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/hydroxyapatite scaffold with unrestricted somatic stem cells for bone regeneration

The combination of scaffolds and cells can be useful in tissue reconstruction. In this study, nanofibrous poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/nanohydroxyapatite (nano-HAp) scaffolds, filled with unrestricted somatic stem cells (USSCs), were used for healing calvarial bone in rat model. The healing effects of these scaffolds, with and without stem cells, in bone regeneration were investigated by computed tomography (CT) analysis and pathology assays after 28 days of grafting. The results of CT analysis showed that bone regeneration on the scaffolds, and the amounts of regenerated new bone for polymer/nano-HAp scaffold with USSC, was significantly greater than the scaffold without cell and untreated control samples. Therefore, the combination of scaffold especially with USSC could be considered as a useful method for bone regeneration.

Electrospun mat with eyelid fat-derived stem cells as a scaffold for ocular epithelial regeneration

The aim of this study was to develop nanofibrous gelatin substrates for eyelid fat stem cell (EFSC) expansion that can serve as a potential alternative substrate to replace human amniotic membrane. Biocompatibility results indicated that all substrates were highly biocompatible, as EFSCs could favorably attach and proliferate on the nanofibrous surfaces. Microscopic figures showed that the EFSC were firmly anchored to the substrates and were able to retain a normal stem cell phenotype. Immunocytochemistry (ICC) and real time-PCR results revealed change in the expression profile of EFSCs grown on nanofibrous substrates when compared to those grown on control in epithelial induction condition. In addition, electrospun gelatin mats especially oriented scaffold provides not only a milieu supporting EFSCs expansion, but also serves as a useful alternative carrier for ocular surface tissue engineering and could be used as an alternative substrate to amniotic membrane.

Rat sciatic nerve reconstruction across a 30 mm defect bridged by an oriented porous PHBV tube with Schwann cell as artificial nerve graft

An oriented poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit has been used to evaluate its efficiency based on the promotion of peripheral nerve regeneration in rats. The oriented porous micropatterned artificial nerve conduit was designed onto the micropatterned silicon wafers, and then their surfaces were modified with oxygen plasma to increase cell adhesion. The designed conduits were investigated by cell culture analyses with Schwann cells (SCs). The conduits were implanted into a 30 mm gap in sciatic nerves of rats. Four months after surgery, the regenerated nerves were monitored and evaluated by macroscopic assessments and histology and behavioral analyses. Results of cellular analyses showed suitable properties of designed conduit for nerve regeneration. The results demonstrated that in the polymeric graft with SCs, the rat sciatic nerve trunk had been reconstructed with restoration of nerve continuity and formatted nerve fibers with myelination. Histological results demonstrated the presence of Schwann and glial cells in regenerated nerves. Functional recovery such as walking, swimming, and recovery of nociceptive function was illustrated for all the grafts especially conduits with SCs. This study proves the feasibility of the artificial nerve graft filled with SCs for peripheral nerve regeneration by bridging a longer defect in an animal model.

Regeneration of full-thickness skin defects using umbilical cord blood stem cells loaded into modified porous scaffolds

In this study, we have demonstrated the ability of cord blood (CB)-derived unrestricted somatic stem cells (USSCs) and chitosan-modified poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffold to promote skin regeneration. Afterward, the scaffolds were evaluated by structural, microscopic, physical, and mechanical assays and cell culture analyses. Results of structural, physical, and mechanical analyses also showed a good resilience and compliance with movement as a skin graft. Cellular experiments showed a better cell adhesion, growth, and proliferation inside the modified scaffolds compared with unmodified ones. In animal models with histological examinations, all groups, excluding the control group especially the groups treated with stem cells, exhibited the most pronounced effect on wound closure, with the statistically significant improvement in wound healing being seen at postoperative day 21. These data suggest that chitosan-modified PHBV scaffold loaded with CB-derived USSCs could significantly contribute to wound repair and be potentially used in the tissue engineering.