Objective(s): Several pathologic complications may lead to defects in urinary bladder tissue or organ loss. In this regard, bladder tissue engineering utilizing electrospun nanofibrous PCL and PCL/chitosan would be promising as replacing structures. Materials and Methods: The resultant nanofibers were characterized for their morphology, diameter and composition by scanning electron microscopy (SEM), and also, FT-IR and CHN analyses. Then, isolation of smooth muscle cells of human urinary bladder biopsies was performed and the obtained cells were characterized by immunocytochemistry (ICC). Thereafter, seeded cells on PCL and PCL/CS nanofibers were assayed for their viability/toxicity, and also, cell-scaffold attachments and cell morphologies were investigated. Results: The findings illustrated that PCL and PCL/CS nanofibers of about 100 nm were successfully fabricated. The obtained scaffolds provided appropriate environment for attachment and expansion of seeded detrusor smooth muscle cells. Biocompatibility of both scaffolds was demonstrated by alamar blue assay. After 7 days of study, cells showed higher viability percentage on PCL/CS nanofibers. Conclusion: Nanofibrous PCL or PCL/CS scaffolds could properly help adhesion and proliferation/growth of human bladder smooth muscle cells (hBSMCs).

Tissue engineering scaffolds produced by electrospinning feature a structural similarity with the natural extracellular matrices. In this study, for the first time, poly(ε-caprolactone) (PCL)/hydroxyapatite (HA) and chitosan/poly(vinyl alcohol) (PVA) were simultaneously electrospun from two different syringes and mixed on a rotating drum to prepare homogeneous nanofibrous composite scaffold. The concentration of the spinning solutions and the ratios of PCL/HA-chitosan/PVA were varied and adjusted to acquire nanofibres with narrow diameter distribution. It was found that the PCL/HA spun fibres became thick and non-uniform in diameter by decreasing the solution concentration and voltage, and yet the effect of flow rate was negligible. Meanwhile, the diameters of chitosan/PVA fibres decreased and became more uniform by decreasing the solution concentration and tip-to-target distance. Furthermore, HA nanocrystals reinforce the scaffold and increase its mechanical strength, though by changing its mechanical behaviour make it more brittle. SEM morphology of the PCL/HA electrospun nanocomposite revealed that HA nanocrystals were kept suspended in solution during the electrospinning process, and laid inside the PCL nanofibres. This feature may provide a mechanism for controlled release of HA nanoparticles in cell culture studies. It was assumed that the nanofibrous composite scaffold of electrospun PCL/HA-chitosan/PVA can potentially be used for the osteogenic differentiation of stem cells.

In this study, a system of dexamethasone sodium phosphate (DEXP)-loaded chitosan nanoparticles embedded in poly-ε-caprolacton (PCL) and gelatin electrospun nanofiber scaffold was introduced with potential therapeutic application for treatment of the nervous system. Besides anti-inflammatory properties, DEXP act through its glucocorticoid receptors, which are involved in the inhibition of astrocyte proliferation and microglial activation. Bovine serum albumin (BSA) was used to improve the encapsulation efficiency of DEXP within chitosan nanoparticles and to overcome its initial burst release. BSA incorporation within the chitosan nanoparticles increased the encapsulation efficiency of DEXP from 30% to 77%. The comparison between DEXP release profile from PCL/gelatin scaffold with and without chitosan nanoparticles revealed that the system of DEXP-BSA-loaded chitosan nanoparticles embedded in electrospun PCL nanofiber scaffold provided a more controlled release pattern of the loaded drug. The scaffolds properties in terms of structure, hydrophilicity, cell compatibility, mechanical property, and biodegradability were further investigated, which might show its potential application for the repair of spinal cord injury.

Background and purpose: Biomaterials, scaffold manufacturing, and design strategies with acceptable mechanical properties are the most critical challenges facing tissue engineering. Experimental approach: In this study, polycaprolactone (PCL) scaffolds were fabricated through a novel three-dimensional (3D) printing method. The PCL scaffolds were then coated with 2% agarose (Ag) hydrogel. The 3D-printed PCL and PCL/Ag scaffolds were characterized for their mechanical properties, porosity, hydrophilicity, and water absorption. The construction and morphology of the printed scaffolds were evaluated via Fourier-Transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The attachment and proliferation of L929 cells cultured on the scaffolds were investigated through MTT assay on the cell culture study upon the 1st, 3rd, and 7th days. Findings/Results: The incorporation of Ag hydrogel with PCL insignificantly decreased the mechanical strength of the scaffold. The presence of Ag enhanced the hydrophilicity and water absorption of the scaffolds, which could positively influence their cell behavior compared to the PCL scaffolds. Regarding cell morphology, the cells on the PCL scaffolds had a more rounded shape and less cell spreading, representing poor cell attachment and cell-scaffold interaction due to the hydrophobic nature of PCL. Conversely, the cells on the PCL/Ag scaffolds were elongated with a spindle-shaped morphology indicating a positive cell-scaffold interaction. Conclusion and implications: PCL/Ag scaffolds can be considered appropriate for tissue-engineering applications.