Translation of Polymeric Microneedles for Treatment of Human Diseases: Recent Trends, Progress, and Challenges.

The ongoing search for biodegradable and biocompatible microneedles (MNs) that are strong enough to penetrate skin barriers, easy to prepare, and can be translated for clinical use continues. As such, this review paper is focused upon discussing the key points (e.g., choice polymeric MNs) for the translation of MNs from laboratory to clinical practice. The review reveals that polymers are most appropriately used for dissolvable and swellable MNs due to their wide range of tunable properties and that natural polymers are an ideal material choice as they structurally mimic native cellular environments. It has also been concluded that natural and synthetic polymer combinations are useful as polymers usually lack mechanical strength, stability, or other desired properties for the fabrication and insertion of MNs. This review evaluates fabrication methods and materials choice, disease and health conditions, clinical challenges, and the future of MNs in public healthcare services, focusing on literature from the last decade.

Effect of Multiaxial Tensile Deformation on the Mechanical Properties of Semiflexible Polymeric Samples.

Molecular dynamics simulation is used to investigate the mechanical properties of the semiflexible polymer during multiaxial tensile deformations. The multiaxial tensile deformations can be imposed in totally or partially constrained modes. These types of deformations may be observed during the sudden deformation of polymeric material in the areas of aerospace, automobile, defense applications, etc. It is found that the constrained multiaxial deformation leads to the formation of nanovoids into the polymer sample. The high Young's modulus and yield strength for the totally constrained modes of tensile deformation are due to the energy required to create voids. The variation in von Misses stress, void volume, and bond order parameter with strain indicates the occurrence of brittle fracture during totally constrained tensile deformations. The partially constrained tensile deformations lead to the improvement in bond order parameter and lesser creation of nanovoids within the system. The system shows the characteristic strain hardening before failures.