Selective hierarchical patterning of silicon nanostructures via soft nanostencil lithography

Microtexture and the Cell/Biomaterial Interface: A Systematic Review and Meta-Analysis of Capsular Contracture and Prosthetic Breast Implants

BACKGROUND

The use of textured breast implants over smooth implants has been widely shown to have a lower incidence of capsular contracture. However, the impact of micropatterning techniques on the incidence of postoperative patient morbidity has not been comprehensively investigated.

OBJECTIVES

The authors sought to examine the incidence of capsular contracture, seroma, and implant rippling among the 3 major micropatterning techniques applied in the manufacturing of textured breast implants.

METHODS

Literature searches of PubMed/Medline and Embase between 1995 and 2017 were performed, and 19 studies were selected for analysis. Data from each study were extracted into a form including mean age, study design, population size, mean follow-up, number of capsular contracture cases, number of seroma cases, and number of rippling cases. Meta-analysis was performed separately for studies that included capsular contracture rates for foam textured implants, imprinted textured implants, and salt-loss textured implants.

RESULTS

The pooled rate of capsular contracture rates in primary augmentation patients was 3.80% (95% CI, 2.19-5.40) for imprinted textured implants, 4.90% (95% CI, 3.16-6.64) for foam textured implants, 5.27% (95% CI, 3.22-7.31) for salt-loss textured implants, and 15.56% (95% CI, 13.31-18.16) for smooth implants. The results of each meta-analysis were summarized on a forest plot depicting the distribution of capsular contracture rates from each study.

CONCLUSIONS

Micropatterning of prosthetic implants could drastically reduce postoperative patient morbidity given the advent of recent technologies that allow for more detailed texturing of implant surfaces.

LEVEL OF EVIDENCE: 4

Scalable Manufacturing of Single Nanowire Devices Using Crack-Defined Shadow Mask Lithography

Single nanowires (NWs) have a broad range of applications in nanoelectronics, nanomechanics, and nanophotonics, but, to date, no technique can produce single sub-20 nm wide NWs with electrical connections in a scalable fashion. In this work, we combine conventional optical and crack lithographies to generate single NW devices with controllable and predictable dimensions and placement and with individual electrical contacts to the NWs. We demonstrate NWs made of gold, platinum, palladium, tungsten, tin, and metal oxides. We have used conventional i-line stepper lithography with a nominal resolution of 365 nm to define crack lithography structures in a shadow mask for large-scale manufacturing of sub-20 nm wide NWs, which is a 20-fold improvement over the resolution that is possible with the utilized stepper lithography. Overall, the proposed method represents an effective approach to generate single NW devices with useful applications in electrochemistry, photonics, and gas- and biosensing.

Manipulation of the Superhydrophobicity of Plasma-Etched Polymer Nanostructures

The manipulation of droplet mobility on a nanotextured surface by oxygen plasma is demonstrated by modulating the modes of hydrophobic coatings and controlling the hierarchy of nanostructures. The spin-coating of polytetrafluoroethylene (PTFE) allows for heterogeneous hydrophobization of the high-aspect-ratio nanostructures and provides the nanostructured surface with "sticky hydrophobicity", whereas the self-assembled monolayer coating of perfluorodecyltrichlorosilane (FDTS) results in homogeneous hydrophobization and "slippery superhydrophobicity". While the high droplet adhesion (stickiness) on a nanostructured surface with the spin-coating of PTFE is maintained, the droplet contact angle is enhanced by creating hierarchical nanostructures via the combination of oxygen plasma etching with laser interference lithography to achieve "sticky superhydrophobicity". Similarly, the droplet mobility on a slippery nanostructured surface with the self-assembled monolayer coating of FDTS is also enhanced by employing the hierarchical nanostructures to achieve "slippery superhydrophobicity" with modulated slipperiness.