Shape memory polymer smart plaster for orthopaedic treatments

Abstract

Shape memory polymer (SMP) is a smart material that can respond to external stimuli and recover its permanent shape after being programmed. Researchers have been interested in SMPs for invasive biomedical applications, but there are many opportunities for non-invasive applications. Thus, in this study, a novel hybrid shape memory polymer nanocomposite smart plaster (SP) is synthesised for non-invasive orthopaedic fractured bone immobilisation. Due to its considerable structural properties, the SP for this study was synthesised with Bisphenol A epoxy, reinforced with E-glass fibres, its bioinspiration qualities were improved incorporating TiO2 nanoparticles. After that, the SP was preserved for three months under five different conditions. This was done to compare their environmental durability and usability for fractured bone immobilisation by analysing the resulting thermomechanical and shape memory properties. In addition, an Abaqus finite element model was developed and validated which can be used to optimise the design and geometrical parameters of the SP. The SP vitro performance was verified, demonstrating a lower limb leg cylindrical cast in less than 10 minutes. The SP at 50oC and two layers of cotton webril produced the optimum results, and the recorded maximum undercast temperature was less than 45oC, which was within the safe limit for human use. Furthermore, the undercast pressure did not surpass 30.2±5.2 mmHg, indicating that the results are equivalent to other bone immobilisation procedures. Therefore, the synthesised SP showed a promising approach to address existing orthopaedic fractured bone limb immobilisation challenges.

Smart shape memory polymers and their significance in biomedical applications: A review

“…The Synthesized SP thus demonstrated a promising strategy for addressing the current orthopedic fractured bone limb immobilization issues. 95,96 Urgent management of orthopedic treatment is frequently needed in hospitals due to slip-and-fall injuries and auto accidents.…”

“…Comparing their environmental robustness and applicability for immobilizing fractured bones was done by examining the resulting thermo‐mechanical and shape‐memory properties. The Synthesized SP thus demonstrated a promising strategy for addressing the current orthopedic fractured bone limb immobilization issues 95,96 …”

“…Additionally, by maintaining a predetermined shape for 30 days (shape fixity ratio > 98%), a unique characteristic of an orthopedic device, optimized control variable's guaranteed the SMP casting material's self‐life. This investigation offers first‐hand pre‐engineered experimental data 95,96 …”

A thermo-viscoelastic constitutive model addressing the cyclic shape memory effect for thermo-induced shape memory polymers

“…Typical applications of TSMPs can be found in these fields, i.e. the text industry, aerospace industry, intelligent robots and biomedicine [6][7][8][9][10]. As a result, the thermo-mechanical behavior and shape memory effect of TSMPs have attracted extensive attention from scholars.…”