ABSTRACT
Precision material design directed by cell biological processes represents a frontier in developing clinically translatable regenerative technologies. While understanding cell-material interactions on multipotent progenitor cells yields insights on target tissue differentiation, equally if not more important is the quantification of indirect multicellular interactions. In this work, the relationship of two material properties, phosphate content and stiffness, of a nanoparticulate mineralized collagen glycosaminoglycan scaffold (MC-GAG) in the expression of an endogenous anti-osteoclastogenic secreted protein, osteoprotegerin (OPG) by primary human mesenchymal stem cells (hMSCs) is evaluated. The phosphate content of MC-GAG requires the type III sodium phosphate symporter PiT-1/SLC20A1 for OPG expression, correlating with ß-catenin downregulation, but is independent of the effects of phosphate ion on osteogenic differentiation. Using three stiffness MC-GAG variants that do not differ significantly by osteogenic differentiation, it is observed that the softest material elicited ≈1.6-2 times higher OPG expression than the stiffer materials. Knockdown of the mechanosensitive signaling axis of YAP, TAZ, ß-catenin and combinations thereof in hMSCs on MC-GAG demonstrates that ß-catenin downregulation increases OPG expression by 1.5-fold. Taken together, these data constitute a roadmap for material properties that can used to suppress osteoclast activation via osteoprotegerin expression separately from the anabolic processes of osteogenesis.
ABSTRACT
Background: Enhanced recovery after surgery (ERAS) protocols have demonstrated success in reducing hospital stay and opioid consumption, but are less well studied in patients undergoing tissue expander-based breast reconstruction (TEBR). This study evaluates the effectiveness of an ERAS postoperative protocol for TEBR at a high-volume center. Methods: All patients undergoing immediate tissue expander reconstruction after the introduction of ERAS were prospectively included from April 2019 to June 2023. An equivalent number of similar patients were retrospectively reviewed before this date as the non-ERAS control. Data included demographics, operative details, postoperative length of stay, inpatient and discharge narcotic quantities, inpatient pain assessments, postoperative radiation, and complications within 90 days. Results: There were 201 patients in each cohort with statistically similar demographics. Patients in the ERAS cohort were more likely to undergo prepectoral reconstruction (83.1% versus 4.5%, P < 0.001), be discharged by day 1 (96.5% versus 70.2%, P < 0.001) and consume lower inpatient milligram morphine equivalent (MME) median (79.8 versus 151.8, P < 0.001). Seroma rates (17.4% versus 3.5%, P < 0.001) and hematoma incidence (4.5% versus 0%, P = 0.004) were higher in the ERAS cohort. Adjusting for implant location, ERAS was associated with a 60.7 MME reduction (ß=-60.7, P < 0.001) and a shorter inpatient duration by 0.4 days (ß =-0.4, P < 0.001). Additionally, prepectoral reconstruction significantly decreased MME (ß=-30.9, P = 0.015) and was the sole predictor of seroma development (odds ratio = 5.2, P = 0.009). Conclusions: ERAS protocols significantly reduce opioid use and hospital stay after TEBR.
ABSTRACT
BACKGROUND: Facial feminization surgery (FFS) is the most common form of facial gender-affirming surgery. One of the current knowledge gaps is the understanding of differences among racial groups in baseline craniofacial norms for transgender and nonbinary patients. METHODS: All patients who sought consultation for FFS and underwent craniofacial computed tomography (CT) scans at a single institution between 2018 and 2023 were included. Patients who underwent previous facial surgeries were excluded. Chart reviews were conducted for patient characteristics, including race, age, hormone therapy duration, and prior gender-affirming surgeries. Racial categorizations included White, Latinx, African American, or Asian. Patients with other or multiracial identities were excluded. Lower face measurements were derived from preoperative facial CT scans. Comparative analyses were performed on all measurements among the racial groups. RESULTS: In this study, 204 patients were included with an average age of 32.0 ± 10.2 years and a median hormone therapy duration of 2.0 years. The notable differences among the racial groups were: 1. Zygomatic width was the largest in Asian patients (13.5 ± 0.6 cm) compared to all other racial groups (p = 0.03), 2. Nasolabial angle was the smallest in African American patients (82.5 ± 13.1 degrees, p < 0.001), 3. Lower face height was the largest in African American patients (6.9 ± 0.7 cm, p < 0.001), and 4. Lateral mandibular flare was the largest in African American patients (0.4 ± 0.1 cm) and the smallest in Latinx patients (0.2 ± 0.1 cm, p < 0.001). CONCLUSIONS: Specific target areas of FFS should be carefully considered to account for possible baseline ethnic differences. Relative facial proportions may also be a more salient surgical planning tool in transgender and gender nonbinary patients rather than absolute measurements alone.
