Recently, there has been growing interest in harnessing genetically engineered polymers to develop responsive biomaterials, such as hydrogels. Unlike their synthetic counterparts, genetically engineered polymers are produced without the use of toxic reagents and can easily be programmed to incorporate desirable hydrogel properties, including bioactivity, biodegradability, and monodispersity. Herein, we report the development of a copolymeric hydrogel that is based on the calcium-dependent protein, calmodulin (CaM). For our system, CaM and M13, a CaM-binding peptide, were incorporated into genetically engineered polymers with intervening linkers containing cleavable sequences. Spectroscopic and multipleparticle tracking (MPT) studies demonstrate that these polymers self-assemble through calcium-stabilized, noncovalent crosslinking to form a soft viscoelastic material. MPT further revealed that gelation is concentration-dependent. Collagenase digests show that the protein polymers are selectively degraded through specific cleavage. The modularity and stimuli-responsiveness of this system suggest its potential as a flexible scaffold for biomedical applications.

Background Breast reduction has a well-chronicled history and remains a common reason for patients to seek plastic surgery consultation. The Wise pattern is the most common skin reduction pattern in the United States. Vertical pattern reduction is also widely used and offers the potential for decreased scar burden. Both patterns have been used with a variety of pedicles for preservation of the nipple areolar complex, which may also impact complication rate and patient satisfaction. There is a preponderance of literature on breast reduction surgery but limited comparative data on the safety profile of these patterns. The purpose of this article is to review the comparative literature, with emphasis on the overall risk of complications. Methods OVID and PubMed were used to query the literature for articles comparing complication rates in both Wise pattern and vertical breast reduction. Inclusion criteria were case series that encompassed both vertical and Wise pattern reductions and cited the rate of complications. Complications included in our analysis of total complication rate were as follows: hematoma, seroma, infection, dehiscence, fat necrosis, skin necrosis, and nipple areolar complex necrosis. We excluded standing cutaneous deformity as a complication. Articles that included oncoplastic breast reductions were also excluded. The primary analysis was an inverse variance-weighted random-effect meta-analysis of overall complication rate, with the association between the technique and overall complication rate quantified using odds ratios. Results Eight articles were identified that met inclusion criteria, representing 963 patients (525 Wise pattern and 438 vertical pattern). The overall complication rate pooled across the studies favored vertical pattern reduction, but the result was not definitive. Conclusions Vertical pattern breast reduction can be done safely. Our statistical analysis found a trend toward decreased complications with vertical reductions, but did not reach statistical significance. Patients seeking breast reduction are a heterogeneous population with respect to breast size, degree of ptosis, body habitus, body mass index, comorbidities, and acceptance of scars. It remains important to individualize the approach to the patient and their needs. More quantitative, comparative data, especially from randomized controlled trials, would be useful to further evaluate the relative safety profiles of the 2 patterns.