Assessing Long-Term Volume Retention in Breast Fat Grafting: A Comparative Study of Lipoaspirate Processing Techniques.

INTRODUCTION: Autologous fat grafting is a method of improving aesthetic outcomes after both breast reconstruction and aesthetic surgery through volume enhancement and tissue contouring. Long-lasting effects are linked to greater patient satisfaction and more optimal augmentation results. Harvesting, processing, and injection techniques may all affect the longevity of deformity filling. Our objective is to evaluate the effect of lipoaspirate processing modality on longitudinal volume retention after surgery. METHODS: A prospective, single-institution, randomized control trial placed consented postmastectomy fat grafting patients into 1 of 3 treatment arms (active filtration, low-pressure decantation, and standard decantation) in a 1:1:1 ratio. A preoperative 3-dimensional scan of the upper torso was taken as baseline. At the 3-month postoperative visit, another 3D scan was taken. Audodesk Meshmixer was used to evaluate the volume change. RESULTS: The volume of fat injected during the initial procedure did not differ significantly between the treatment arms (P > 0.05). Both active filtration and low-pressure decantation resulted in higher percentage volume retention than traditional decantation (P < 0.05). Active filtration and low-pressure decantation exhibited comparable degrees of fat maintenance at 3 months (P > 0.05). DISCUSSION: Compared with using traditional decantation as the lipoaspirate purification technique, active filtration and low-pressure decantation may have led to higher levels of cell viability by way of reduced cellular debris and other inflammatory components that may contribute to tissue resorption and necrosis. Further immunohistochemistry studies are needed to examine whether active filtration and low-pressure decantation lead to lipoaspirates with more concentrated viable adipocytes, progenitor cells, and factors for angiogenesis.

Biomechanics of a Plant-Derived Sealant for Corneal Injuries.

Purpose: The corneal epithelium has a glycocalyx composed of membrane-associated glycoproteins, mucins, and galactin-3. Similar to the glycocalyx in visceral tissues, the corneal glycocalyx functions to limit fluid loss and minimize frictional forces. Recently, the plant-derived heteropolysaccharide pectin has been shown to physically entangle with the visceral organ glycocalyx. The ability of pectin to entangle with the corneal epithelium is unknown. Methods: To explore the potential role of pectin as a corneal bioadhesive, we assessed the adhesive characteristics of pectin films in a bovine globe model. Results: Pectin film was flexible, translucent, and low profile (80 µm thick). Molded in tape form, pectin films were significantly more adherent to the bovine cornea than control biopolymers of nanocellulose fibers, sodium hyaluronate, and carboxymethyl cellulose (P < 0.05). Adhesion strength was near maximal within seconds of contact. Compatible with wound closure under tension, the relative adhesion strength was greatest at a peel angle less than 45 degrees. The corneal incisions sealed with pectin film were resistant to anterior chamber pressure fluctuations ranging from negative 51.3 ± 8.9 mm Hg to positive 214 ± 68.6 mm Hg. Consistent with these findings, scanning electron microscopy demonstrated a low-profile film densely adherent to the bovine cornea. Finally, the adhesion of the pectin films facilitated the en face harvest of the corneal epithelium without physical dissection or enzymatic digestion. Conclusions: We conclude that pectin films strongly adhere to the corneal glycocalyx. Translational Relevance: The plant-derived pectin biopolymer provides potential utility for corneal wound healing as well as targeted drug delivery.

Kinetics of Pectin Biopolymer Facial Erosion Characterized by Fluorescent Tracer Microfluidics.

Pectin is a plant-derived heteropolysaccharide that has been implicated in drug development, tissue engineering, and visceral organ repair. Pectin demonstrates remarkable biostability in a variety of physiologic environments but is biodegradable in water. To understand the dynamics of pectin biodegradation in basic environments, we developed a microfluidics system that facilitated the quantitative comparison of pectin films exposed to facial erosion. Pectin biodegradation was assessed using fluorescein tracer embedded in pectin, trypan blue quenching of released fluorescence, and highly sensitive microfluorimetry. The microfluidic perfusate, delivered through 6 um-pore synthetic membrane interface, demonstrated nonlinear erosion of the pectin film; 75% of tracer was released in 28 h. The microfluidics system was used to identify potential modifiers of pectin erosion. The polyphenolic compound tannic acid, loaded into citrus pectin films, demonstrated a dose-dependent decrease in pectin erosion. Tannic acid had no detectable impact on the physical properties of citrus pectin including adhesivity and cohesion. In contrast, tannic acid weakened the burst strength and cohesion of pectins derived from soy bean and potato sources. We conclude that facial erosion may explain the biostability of citrus pectin on visceral organ surfaces as well as provide a useful method for identifying modifiers of citrus pectin biodegradation.

Optical and Mechanical Properties of Self-Repairing Pectin Biopolymers.

Pectin's unique physicochemical properties have been linked to a variety of reparative and regenerative processes in nature. To investigate the effect of water on pectin repair, we used a 5 mm stainless-steel uniaxial load to fracture glass phase pectin films. The fractured gel phase films were placed on a 1.5-1.8 mm thick layer of water and incubated for 8 h at room temperature and ambient humidity. There was no immersion or agitation. The repaired pectin film was subsequently assessed for its optical and mechanical properties. Light microscopy demonstrated repair of the detectable fracture area and restoration of the films' optical properties. The burst strength of the repaired film declined to 55% of the original film. However, its resilience was restored to 87% of the original film. Finally, a comparison of the initial and post-repair fracture patterns demonstrated no recurrent fissures in the repaired glass phase films. The water-induced repair of the pectin film was superior to the optical and mechanical properties of the repaired films composed of nanocellulose fibers, sodium hyaluronate, and oxidized cellulose. We conclude that the unique physicochemical properties of pectin facilitate the water-induced self-repair of fractured pectin films.

Methodology to streamline flow cytometric-based detection of early stage Plasmodium parasitemia in mice.

Murine infection models are needed to develop therapeutics and vaccines to combat the Plasmodium parasites causing malaria. Herein, we describe an easy to perform flow cytometry-based methodology for detecting green fluorescent protein-expressing Plasmodium berghei in the peripheral red blood cells (RBC) of mice. This methodology uses one-step staining and simplified gating strategies to streamline the process of Plasmodium quantification and can detect parasitemia at an earlier time point after infection compared to traditional light microscopy-based techniques.