Morphological and biochemical analysis of cells cultured on fibrous poly(ε-caprolactone) scaffolds with different degrees of fiber alignment produced by solution blow spinning.

BACKGROUND: Bioresorbable materials are compounds that decompose in physiological mediums both in vitro and in vivo and are used as an alternative to temporary implants in injured tissues. The aim of this study was to analyze the morphology and cytochemistry of cells grown on fibrous poly(ε-caprolactone) (PCL) scaffolds and to measure cell metabolism parameters by biochemical analysis of the conditioned culture medium from cells grown on the scaffolds. METHODS: Fibrous PCL scaffolds were used under the following conditions: unaligned fibers (NA), fibers aligned at 150 rpm (A150), and fibers aligned at 300 rpm (A300). Vero cells were cultured on these scaffolds for 24 h, 48 h, and 72 h. Samples were analyzed by SEM, MicroCT, cytochemistry, and culture medium biochemistry. RESULTS: The results of the cytochemical analysis showed cells were confluent and well spread on the culture plate, while cells grown on the polymeric scaffold, exhibited an elongated morphology. In the biochemical analyses, no significant differences were observed in the expression of alkaline phosphatase or in the levels of cholesterol or total protein in the culture medium. The different materials do not seem to promote changes in the expression or metabolism of these molecules. Only glucose was markedly reduced in the culture medium of cells grown on either aligned or unaligned scaffolds for 48 h or 72 h. This finding indicates the intense energy requirements of cells grown on these scaffolds. CONCLUSION: PCL fibers showed a great capacity to support cell growth. These data reinforce the interpretation that cells grow satisfactorily on PCL scaffolds.

In Vitro Hydrodynamic Evaluation of a Scaffold for Heart Valve Tissue Engineering.

Although prosthetic heart valves have saved many lives, the search for a living substitute continues with the aid of tissue engineering. Much progress has been made so far, but the translation of this technology to clinical reality remains a challenge, especially due to the structural complexity of heart valves and the harsh environment they are in. In a joint effort, researchers from Federal University of ABC and Institute Dante Pazzanese of Cardiology have conceived a new bioresorbable scaffold for heart valve tissue engineering (HVTE), whose hydrodynamic performance was first assessed and described in this work. The scaffold was studied at the mitral position of a left heart simulator from Escola Politécnica of the University of São Paulo, under 60 bpm and with no cell seeding. In this condition, two-dimensional particle image velocimetry was performed to investigate the flow during diastolic and systolic phases. The results indicate that the scaffold can withstand the required intraventricular pressures for a simulated normal physiologic condition in a bioreactor. Furthermore, the averaged (N = 150) velocity vector maps showed a smooth and well-distributed flow during diastole and qualitatively demonstrated no-significant regurgitation at systole.

Comparative study of aligned and nonaligned poly(ε-caprolactone) fibrous scaffolds prepared by solution blow spinning.

Fibrous scaffolds have become popular in tissue engineering (TE) due to their morphological resemblance to extracellular matrix components. While electrospinning is the most common technique in the field, solution blow spinning is an emerging technique with great potential. One of its many advantages is that it can produce aligned fibers with a very simple experimental setup. This work aimed to fabricate poly(ε-caprolactone) mats with aligned fibers and compare them to nonaligned ones. For that, samples were produced using three rotational speeds of a cylindrical collector and characterized in terms of fiber alignment and diameter, mechanical properties, wettability, and biological response. Results showed that with a static collector, fibers were randomly deposited and nonaligned. As the speed was increased, the fibers began to align (as proven by image analysis), resulting in a change in mechanical behavior, but no differences in fiber diameter. Cells cultured on aligned samples were more elongated, and a higher alignment degree seemed to favor cellular growth. The results confirmed the potential of this up-and-coming technique to produce aligned fibers for TE. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1462-1470, 2019.

Comparative study of aligned and nonaligned poly(ε-caprolactone) fibrous scaffolds prepared by solution blow spinning

Fibrous scaffolds have become popular in tissue engineering (TE) due to their morphological resemblance to extracellular matrix components. While electrospinning is the most common technique in the field, solution blow spinning is an emerging technique with great potential. One of its many advantages is that it can produce aligned fibers with a very simple experimental setup. This work aimed to fabricate poly (ε-caprolactone) mats with aligned fibers and compare them to nonaligned ones. For that, samples were produced using three rotational speeds of a cylindrical collector and characterized in terms of fiber alignment and diameter, mechanical properties, wettability, and biological response. Results showed that with a static collector, fibers were randomly deposited and nonaligned. As the speed was increased, the fibers began to align (as proven by image analysis), resulting in a change in mechanical behavior, but no differences in fiber diameter. Cells cultured on aligned samples were more elongated, and a higher alignment degree seemed to favor cellular growth. The results confirmed the potential of this up-and-coming technique to produce aligned fibers for TE. (AU)