Pneumatospinning Apparatus

Designing an experimental set-up for tissue generation via pneumatospinning scaffolds.

MAE 156B Senior Design Project Spring 2022

University of California San Diego

Background

Menisci are an essential tissue in knee joints that contribute to load distribution, knee stability, and protect articular cartilage. Injuries to menisci are common among young athletes in the United States.

Loss of meniscal tissue alters joint loading dynamics, leading to joint destabilization and finally a progression to osteoarthritis. In order to replace the damaged menisci, meniscal substitutions have been proposed for partial and total meniscus replacement.

What is Pneumatospinning?

Pneumatospinning is a novel method of generating fibrous scaffolds in tissue engineering. Pneumatospinning is a simple and efficient process that relies on gas pressure to fabricate thick scaffolds for optimum cell growth. Pneumatospinning can produce fibers with diameters ranging from 70nm to as large as 1 00mm by tuning process variables such as the polymer injection rate and concentration, temperature, air/gas pressure, and nozzle geometry.

Objectives

We hope to fabricate an experimental setup that will allow for the study and test of different parameters in order to more efficiently generate scaffolds in tissue generation.

A controllable and accurate delivery system for a fluid solution.
A modular nozzle system with coaxial needles and variable nozzle diameters.
An air compressor with a flow rate control valve. This must be controllable and accurate.
A motorized collector mounting stage that permits changing orientation and distance from the airbrush.
A rotating drum or spinning collector that changes angles and distance from the nozzle.
There must be humidity control which maintains humidity levels below 55% with a dehumidifier.

Performance Results

The device is able to lower chamber humidity level with respect to ambient humidity by approximately 10% through a 4°F increase in temperature. The resulting tissue scaffold is adequate in fiber formation, pore size, and dryness. Despite being a humid day, border lining on the failure condition of 55%, the scaffold produced by the modular device was sufficiently dry, lacking any major globules that the old set up may have had.

Summary of Results

The design proved successful due to its ability to generate tissue engineering scaffolds. The pneumatospinning apparatus is a functional, modular, and automated device that simplifies the experimental process needed to create tissue fibers by pneumatospinning. With a sealed chamber and humidity control, this device allows for research to occur on any given day despite the humidity levels. This has proven significant improvements in parameter control and efficiency in comparison to the current model. The modularity and ease of fabrication of this device will allow for further modifications and design iterations as needed to continue experimenting with tissue engineering. With the improvements made to pneumatospinning tissue fibers, further research may be developed to design an effective solution to meniscus tears.