Tailoring the void space and mechanical properties in electrospun scaffolds towards physiological ranges.

Electrospinning has proven to be a promising method to produce scaffolds for tissue engineering despite the frequently encountered limitations in 3-dimensional tissue formation due to a lack of cell infiltration. To fully unlock the potential of electrospun scaffolds for tissue engineering, the void space within the fibrous network needs to be increased substantially and in a controlled manner. Low-temperature electrospinning (LTE) increases the fiber to fiber distance by embedding ice particles as void spacers during fiber deposition. Scaffold porosities up to 99.5% can be reached and in line with the increase in void space, the mechanical properties of the scaffolds shift towards the range for native biological tissue. While both the physiological mechanical properties and high porosity were promising for tissue engineering applications, control of the porosity in three dimensions was still limited when using LTE methods. Based on a range of LTE spun scaffolds made of poly(lactic acid) and poly(ε-caprolactone), we found that changing the ratio between the rate of ice crystal formation and polymer fiber deposition only had a small effect on the 3D-porosity of the final scaffold architecture. Varying the fiber stiffness, however, offers considerable control over the scaffold void space.

A new custom moldable external neck brace (ENB 2.0) to improve hands-free speech in laryngectomized patients.

OBJECTIVES/HYPOTHESIS: The majority of laryngectomy patients fail to use a hands-free valve on a daily basis, mainly due to fixation problems of the adhesive baseplate housing. To support adhesive housings during hands-free speech a new external neck brace (ENB 2.0) was developed. The effect of the brace was assessed in terms of a qualitative assessment, adhesive lifetime, maximum phonation time and patient self-reports. STUDY DESIGN: Twenty laryngectomees participated in this randomized, prospective, crossover trial. METHODS: All participants used the Provox hands-free HME valve with an Xtrabase adhesive for 1 month, 2 weeks with an ENB 2.0, and 2 weeks without. Outcomes were compared with the previous model of the external neck brace (ENB 1.0). RESULTS: The average total number of adhesive baseplates used during the trial was 16.7 in the non-brace group versus 10.9 in the brace group (P = 0.05). The number of daily replacements was 1.4 in the non-brace group and 1.1 in the brace group (P = 0.025). The average time a hands-free valve was worn per baseplate was 9.5 hours when wearing a neck brace versus 7.3 hours without brace (P = 0.09).The majority (81%) of the patients considered the neck brace 2.0 as a welcome addition to improve hands-free speech after laryngectomy and would use it if prescribed (88%). CONCLUSION: The new model of the neck brace reduces the number of baseplate replacements during hands-free speech and is considered as a helpful device by 81% of the participants.