Effect of Duration of Feminizing Hormone Therapy on Facial Fat Volumes.

BACKGROUND: Gender-affirming feminizing hormone therapy induces body fat redistribution. However, the amount and timing of facial fat changes in response to feminizing hormone therapy are unknown, despite being relevant to counseling and surgical planning for facial gender-affirming surgery. The authors assessed the influence of feminizing hormone therapy duration on malar and temporal fat volume. METHODS: Malar and temporal fat volumes were compared using computed tomography in transfeminine patients (age, 20 to 29 years; body mass index, 18.5 to 24.9) treated with feminizing hormone therapy for less than 2 years versus 2 years or longer. Patients with previous surgical or nonsurgical facial soft-tissue interventions were excluded. Multivariable linear regressions evaluated the contribution of hormone therapy duration to malar and temporal fat volumes. RESULTS: A total of 45 patients were included, 30 (66.7%) treated with feminizing hormone therapy for 2 years or longer and 15 (33.3%) treated for less than 2 years (median [interquartile range], 44.5 [33.5 to 65.6] versus 15.0 [11.0 to 18.0] months; P < 0.001). Patients treated with hormone therapy for 2 years or longer demonstrated a 1.6-fold greater malar fat volume (5.5 [4.2 to 6.3] versus 3.4 [2.3 to 4.2] cm 3 ; P < 0.001) and 1.4-fold greater temporal fat volume (2.8 [2.4 to 3.6] cm 3 versus 2.0 [1.7 to 2.4] cm 3 ; P = 0.01) compared with those treated for less than 2 years. When accounting for other contributory variables, such as body mass index, skull size, and total soft-tissue depth, in multivariable linear regression models, hormone therapy duration of 2 years or longer independently predicted higher malar (ß = 0.51, P < 0.001) and temporal (ß = 0.32, P = 0.02) fat volumes. CONCLUSION: Feminizing hormone therapy increases malar and temporal fat volumes by approximately 2 cm 3 and 0.8 cm 3 for each area, respectively, after 2 years of treatment. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

The Type I+ Forehead in Facial Feminization Surgery.

BACKGROUND: Feminizing fronto-orbital reconstruction involves one of four possibilities with the Ousterhout Type III anterior table frontal sinus osteotomy and setback performed in most patients while the Type I reduction recontouring is reserved for patients without frontal sinuses or thick anterior tables. However, patients with frontal sinuses and either a moderately thick anterior table or a shallow frontal sinus in the sagittal plane represent an intermediate morphology. For such morphologies, we introduce the novel Type I+ fronto-orbital reconstruction technique, consisting of frontal bone recontouring supplemented with anterior table reconstruction and split cranial bone graft. METHODS: Transgender and gender non-conforming patients who underwent Type I+ or Type III feminizing fronto-orbital reconstruction (2019-2023) were included for retrospective review and comparison of techniques. RESULTS: In the 123 patients (mean age 32.2 ± 9.5 years) included, 6.5% underwent Type I+ and 94.5% underwent Type III feminizing fronto-orbital reconstruction. Morphologically, Type I+ patients displayed a shallower frontal sinus compared to Type III patients (median anterior to posterior table depth 4.1[interquartile range, IQR, 1.1-5.0] versus 9.8[IQR 7.5-12.0]mm, p<0.001). At the maximum prominence, Type I+ patients also demonstrated thicker anterior tables compared to Type III patients (median 6.6[IQR 5.0-8.8] versus 2.2[IQR 0.4-4.7]mm, p=0.001). Patients receiving Type I+ procedures underwent an anterior table reduction of 2.7±1.2mm versus 4.2 ± 1.2mm for Type III procedures in the sagittal plane (p=0.002). CONCLUSIONS: The current work introduces a novel solution to an intermediate frontal sinus phenotype for gender-affirming facial feminization surgery. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Virtual Modeling in Gender-Affirming Facial Masculinization Surgery.

SUMMARY: The increase in access to facial gender-affirming surgery has resulted in a rise in facial feminization surgeries for transfeminine and gender non-binary populations. However, refined execution of facial masculinization is challenged by the lack of defined measurements for facial augmentation, the lack of long-term predictability in autologous bone grafting in augmentation procedures, and the lack of precision in traditional facial augmentation procedures with generic alloplastic implants. In this work, we describe an innovation in facial masculinization surgery using modern reconstructive craniofacial surgical techniques with preoperative virtual modeling and the fabrication of three-dimensionally printed, patient-specific custom implants.

Correlating Material Properties to Osteoprotegerin Expression on Nanoparticulate Mineralized Collagen Glycosaminoglycan Scaffolds.

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.

Medicaid coverage for gender-affirming surgery: A state-by-state review.

OBJECTIVE: To systematically review Medicaid policies state-by-state for gender-affirming surgery coverage. DATA SOURCES AND STUDY SETTING: Primary data were collected for each US state utilizing the LexisNexis legal database, state legislature publications, and Medicaid manuals. STUDY DESIGN: A cross-sectional study evaluating Medicaid coverage for numerous gender-affirming surgeries. DATA COLLECTION/EXTRACTION METHODS: We previously reported on state health policies that protect gender-affirming care under Medicaid coverage. Building upon our prior work, we systematically assessed the 27 states with protective policies to determine coverage for each type of gender-affirming surgery. We analyzed Medicaid coverage for gender-affirming surgeries in four domains: chest, genital, craniofacial and neck reconstruction, and miscellaneous procedures. Medicaid coverage for each type of surgery was categorized as explicitly covered, explicitly noncovered, or not described. PRINCIPAL FINDINGS: Among the 27 states with protective Medicaid policies, 17 states (63.0%) provided explicit coverage for at least one gender-affirming chest procedure and at least one gender-affirming genital procedure, while only eight states (29.6%) provided explicit coverage for at least one craniofacial and neck procedure (p = 0.04). Coverage for specific surgical procedures within these three anatomical domains varied. The most common explicitly covered procedures were breast reduction/mastectomy and hysterectomy (n = 17, 63.0%). The most common explicitly noncovered surgery was reversal surgery (n = 12, 44.4%). Several states did not describe the specific surgical procedures covered; thus, final coverage rates are indeterminate. CONCLUSIONS: In 2022, 52.9% of states had health policies that protected gender-affirming care under Medicaid; however, coverage for various gender-affirming surgical procedures remains both variable and occasionally unspecified. When specified, craniofacial and neck reconstruction is the least covered anatomical area compared with chest and genital reconstruction.

United States Health Policies on Gender-Affirming Care in 2022.

BACKGROUND: Within the United States, access to gender-affirming operations covered by health insurance has increased dramatically over the past decade. However, the perpetually changing landscape and inconsistencies of individual state health policies governing private and public insurance coverage present a lack of clarity for reconstructive surgeons and other physicians attempting to provide gender-affirming care. This work systematically reviewed the current U.S. health policies for both private insurance and Medicaid on a state-by-state basis. METHODS: Individual state health policies in effect as of August of 2022 on gender-affirming care were reviewed using the LexisNexis legal database, state legislature publications, and Medicaid manuals. Primary outcomes were categorization of policies as protective, restrictive, or unclear for each state. Secondary outcomes included analyses of demographics covered by current health policies and geographic differences. RESULTS: Protective state-level health policies related to gender-affirming care were present in approximately half of the nation for both private insurance (49.0%) and Medicaid (52.9%). Explicitly restrictive policies were found in 5.9% and 17.6% of states for private insurance and Medicaid, respectively. Regionally, the Northeast and West had the highest rates of protective policies, whereas the Midwest and South had the highest rates of restrictive policies on gender-affirming care. CONCLUSIONS: State-level health policies on gender-affirming care vary significantly across the United States with regional associations. Clarity in the current and evolving state-specific health policies governing gender-affirming care is essential for surgeons and physicians caring for transgender and gender-diverse individuals.

Long-term outcomes of sphincter pharyngoplasty in patients with cleft palate.

OBJECTIVE: The purpose of this study was to evaluate long-term outcomes of sphincter pharyngoplasties, including speech outcomes, revision surgeries, and postoperative incidence of obstructive sleep apnea (OSA). DESIGN: Retrospective matched-cohort study SETTING: Two craniofacial centers in Los Angeles, CA PATIENTS: Patients (n = 166) with cleft lip and palate (CLP) or isolated cleft palate (iCP) who underwent sphincter pharyngoplasty from 1992 to 2022 were identified. An age- and diagnosis-matched control group of 67 patients with CLP/iCP without velopharyngeal insufficiency (VPI) was also identified. INTERVENTIONS: The pharyngoplasty group underwent sphincter pharyngoplasty, whereas the non-VPI group had no history of VPI surgery or sphincter pharyngoplasty. MAIN OUTCOME MEASURES: Postoperative speech outcomes, revision surgeries, and incidence of OSA were evaluated. Multivariable regression was used to evaluate independent predictors of OSA. RESULTS: Among the patients in the pharyngoplasty cohort, 63.9% demonstrated improved and sustained speech outcomes after a single pharyngoplasty, with a median postoperative follow-up of 8.8 years (interquartile range [IQR], 3.6-12.0 years). One-third of the patients who underwent pharyngoplasty required a revision surgery, with a median time to primary revision of 3.9 years (IQR, 1.9-7.0 years). OSA rates increased significantly among the pharyngoplasty cohort, from 3% before surgery to 14.5% after surgery (p < 0.001). The average time from sphincter pharyngoplasty to OSA diagnosis was 4.4 ± 2.4 years. Multivariable analysis results indicated that sphincter pharyngoplasty surgery was independently associated with a fourfold increase in OSA (p = 0.03). CONCLUSIONS: Although sphincter pharyngoplasty remains successful in improving long-term speech outcomes, persistent OSA is a sequela that should be monitored beyond the immediate postoperative period.

Bone-Anchored Maxillary Protraction for Adolescents with Cleft Palate and Class III Malocclusion: A Case Series.

To describe the long-term treatment course of bone-anchored maxillary protraction (BAMP) and evaluate orthognathic surgical indications after BAMP.Retrospective case series.Craniofacial/Cleft Palate Program at the Orthopaedic Institute for Children in Los Angeles, CA.Twelve male patients with cleft palate (CP), unilateral cleft lip and palate (UCLP), or bilateral cleft lip and palate (BCLP) and Class III malocclusion treated with BAMP (mean age: 11.4 ± 2.6 years) were included.BAMP treatment was performed by placement of bone-anchored maxillary and mandibular plates connected with intraoral Class III dental elastics or maxillary plates connected to a facemask.We retrospectively assessed BAMP treatment variables, including age at surgery, revision surgeries, and treatment duration. The primary goal was correction to class I occlusion.Twelve patients underwent BAMP treatment for an average of 4.4 ± 2.4 years. Two patients were corrected to class I occlusion at the time of this report. Le Fort I advancement was no longer required in two patients (16.7%), it was required for nine patients (75.0%) and was completed for one patient following BAMP treatment (8.3%).This preliminary report demonstrated that BAMP treatment may be associated with a minimal reduction in the requirement for Le Fort I advancement at skeletal maturity. Future studies with larger sample sizes are necessary to confirm this association.

Functional outcomes of nerve allografts augmented with mesenchymal stem cells and surgical angiogenesis in a rat sciatic nerve defect model.

BACKGROUND: Motor function recovery following acellular nerve allograft (ANA) repair remains inferior to autologous nerve reconstruction. We investigated the functional recovery of ANAs after combined mesenchymal stem cell (MSC) delivery and surgical angiogenesis in a rat sciatic nerve defect model. METHODS: In 100 Lewis rats, unilateral sciatic nerve defects were reconstructed with (I) autografts, (II) ANAs, (III) ANAs wrapped with a superficial inferior epigastric artery fascial (SIEF) flap, combined with either (IV) undifferentiated MSCs or (V) Schwann cell-like differentiated MSCs. The tibialis anterior muscle area was evaluated during the survival period using ultrasonography. Functional recovery, histomorphometry, and immunofluorescence were assessed at 12 and 16 weeks. RESULTS: At 12 weeks, the addition of surgical angiogenesis and MSCs improved ankle contractures. The SIEF flap also significantly improved compound muscle action potential (CMAP) outcomes compared with ANAs. Autografts outperformed all groups in muscle force and weight. At 16 weeks, ankle contractures of ANAs remained inferior to autografts and SIEF, whereas the CMAP amplitude was comparable between groups. The muscle force of autografts remained superior to all other groups, and the muscle weight of ANAs remained inferior to autografts. No differences were found in histomorphometry outcomes between SIEF groups and ANAs. Vascularity, determined by CD34 staining, was significantly higher in SIEF groups compared with ANAs. CONCLUSIONS: The combination of surgical angiogenesis and MSCs did not result in a synergistic improvement in functional outcomes. In a short nerve gap model, the adipofascial flap may provide sufficient MSCs to ANAs without additional ex vivo MSC seeding.

Duration of Feminizing Hormone Therapy on Facial Fat Volumes.

BACKGROUND: Gender-affirming feminizing hormone therapy induces body fat redistribution. However, the amount and timing of facial fat changes in response to feminizing hormone therapy are unknown, albeit relevant to counseling and surgical planning for facial gender-affirming surgery. In this work, we assessed the influence of feminizing hormone therapy duration on malar and temporal fat volume. METHODS: Malar and temporal fat volumes were compared using computed tomography in transfeminine patients (age 20-29 years, body mass index [BMI] 18.5-24.9) treated with feminizing hormone therapy for <2 years versus ≥2 years. Patients with prior surgical or non-surgical facial soft-tissue interventions were excluded. Multivariable linear regressions evaluated the contribution of hormone therapy duration to malar and temporal fat volumes. RESULTS: 45 patients were included with 30 patients (66.7%) treated with feminizing hormone therapy for ≥2 years and 15 patients (33.3%) treated for <2 years (median[interquartile range, IQR]: 44.5[33.5-65.6] vs. 15.0[11.0-18.0] months, p<0.001). Patients treated with hormone therapy for ≥2 years demonstrated a 1.6-fold greater malar fat volume (5.5[4.2-6.3] vs. 3.4[2.3-4.2] cm 3,p<0.001) and 1.4-fold greater temporal fat volume (2.8[2.4-3.6] cm 3 vs. 2.0[1.7-2.4] cm 3, p=0.01) compared to those treated for <2 years. When accounting for other contributory variables such as BMI, skull size, and total soft-tissue depth in multivariable linear regression models, hormone therapy duration ≥2 years independently predicted higher malar (ß=0.51, p<0.001) and temporal (ß=0.32, p=0.02) fat volumes. CONCLUSIONS: Feminizing hormone therapy increases malar and temporal fat volumes by approximately 2 cm 3 and 0.8 cm 3 for each area, respectively, after 2 years of treatment.

An enhanced recovery after surgery protocol for facial feminization surgery reduces perioperative opioid usage, pain, and hospital stay.

BACKGROUND: Prescription drug misuse in transgender individuals is estimated to be three times higher than that of the general population in the United States, suggesting that opioid-reduction strategies deserve significant consideration in gender-affirming surgeries. In this work, we describe the implementation of an enhanced recovery after surgery (ERAS) protocol to reduce opioid use after facial feminization surgery. METHODS: A total of 79 patients who underwent single-stage facial feminization surgery before (n = 38) or after (n = 41) ERAS protocol implementation were included. Primary outcomes assessed were perioperative opioid consumption (morphine equivalent dose/kilogram, MED/kg), average patient-reported pain scores, and length of hospital stay. Comparisons between groups and multivariable linear regression analyses were conducted to define the contribution of the ERAS protocol to each of the three primary outcomes. RESULTS: Age, body mass index, mental health diagnoses, and length of surgery did not differ between pre-ERAS and ERAS groups. Compared to pre-ERAS patients, patients treated under the ERAS protocol consumed less opioids (median [interquartile range, IQR], 0.8 [0.5-1.1] versus 1.5 [1.0-2.1] MED/kg, p < 0.001), reported lower pain scores (2.5 ± 1.8 versus 3.7 ± 1.6, p = 0.002), and required a shorter hospital stay (median [IQR], 27.3 [26.3-49.8] versus 32.4 [24.8-39.1] h, p < 0.001). When controlling for other contributing variables such as previous gender-affirming surgeries, mental health diagnoses, and length of surgery using multivariable linear regression analyses, ERAS protocol implementation independently predicted reduced opioid use, lower pain scores, and shorter hospital stay after facial feminization surgery. CONCLUSIONS: The current work details an ERAS protocol for facial feminization surgery that reduces perioperative opioid consumption, patient-reported pain scores, and hospital stays.

Dynamic Seeding versus Microinjection of Adipose-Derived Mesenchymal Stem Cells to Acellular Nerve Allograft Reconstructions.

BACKGROUND: Functional recovery following acellular nerve allograft (ANA) reconstructions remains inferior to autologous nerve grafting, but have demonstrated improved outcomes with the addition of adipose-derived mesenchymal stem cells (MSC). Controversy exists regarding the optimal cell delivery method to enhance ANA reconstructions. We investigated the functional recovery of ANAs after dynamic seeding versus microinjection of MSCs. METHODS: Forty Lewis rats underwent reconstruction of a 10-mm sciatic nerve defect. Animals were divided into four groups: reversed autograft, ANA alone, ANA dynamically seeded, or ANA injected with MSCs. During the survival period, ultrasound measurements of the tibialis anterior (TA) muscle cross-sectional area were performed. At 12 weeks, functional recovery was evaluated using measurements of ankle contracture, compound muscle action potential (CMAP), maximum isometric tetanic force (ITF), muscle mass, histomorphometry, and immunofluorescence. RESULTS: The dynamic seeding and microinjection groups demonstrated higher cross-sectional TA muscle area recovery than autografts and ANAs alone at week 8 and week 4 and 8, respectively. The ankle contracture and CMAP amplitude recovery were superior in autografts and both seeding methods compared to ANAs alone. The microinjection group demonstrated significantly higher ITF, muscle mass, and number of axons compared to ANAs alone. Both seeding methods showed higher CD34 densities compared to ANAs alone. No significant differences between dynamic seeding and microinjection were observed for both functional and histological outcomes. CONCLUSIONS: The addition of MSCs to ANAs demonstrated earlier motor regeneration compared to autografts and ANAs alone. Both seeding methods improved functional outcomes in the rat sciatic nerve defect model. CLINICAL RELEVANCE STATEMENT: Future clinical applications of stem cell-based nerve reconstructions are dependent on determining optimum delivery methods, which are technically feasible, reproducible, cost-efficient, and timely.

Sarcopenia Best Predicts Complications in Free Flap Breast Reconstruction.

Breast reconstruction remains a major component of the plastic surgeon's repertoire, especially free-flap breast reconstruction (FFBR), though this is a high-risk surgery in which patient selection is paramount. Preoperative predictors of complication remain mixed in their utility. We sought to determine whether the sarcopenia score, a validated measure of physiologic health, outperforms the body mass index (BMI) and modified frailty index (mFI) in terms of predicting outcomes. Methods: All patients with at least 6-months follow-up and imaging of the abdomen who underwent FFBR from 2013 to 2022 were included in this study. Appropriate preoperative and postoperative data were included, and sarcopenia scores were extracted from imaging. Complications were defined as any unexpected outcome that required a return to the operating room or readmission. Statistical analysis and regression were performed. Results: In total, 299 patients were included. Patients were split into groups, based on sarcopenia scores. Patients with lower sarcopenia had significantly more complications than those with higher scores. BMI and mFI both did not correlate with complication rates. Sarcopenia was the only independent predictor of complication severity when other factors were controlled for in a multivariate regression model. Conclusions: Sarcopenia correlates with the presence of severe complications in patients who undergo FFBR in a stronger fashion to BMI and the mFI. Thus, sarcopenia should be considered in the preoperative evaluation in patients undergoing FFBR.

Convergence of Calcium Channel Regulation and Mechanotransduction in Skeletal Regenerative Biomaterial Design.

Cells are known to perceive their microenvironment through extracellular and intracellular mechanical signals. Upon sensing mechanical stimuli, cells can initiate various downstream signaling pathways that are vital to regulating proliferation, growth, and homeostasis. One such physiologic activity modulated by mechanical stimuli is osteogenic differentiation. The process of osteogenic mechanotransduction is regulated by numerous calcium ion channels-including channels coupled to cilia, mechanosensitive and voltage-sensitive channels, and channels associated with the endoplasmic reticulum. Evidence suggests these channels are implicated in osteogenic pathways such as the YAP/TAZ and canonical Wnt pathways. This review aims to describe the involvement of calcium channels in regulating osteogenic differentiation in response to mechanical loading and characterize the fashion in which those channels directly or indirectly mediate this process. The mechanotransduction pathway is a promising target for the development of regenerative materials for clinical applications due to its independence from exogenous growth factor supplementation. As such, also described are examples of osteogenic biomaterial strategies that involve the discussed calcium ion channels, calcium-dependent cellular structures, or calcium ion-regulating cellular features. Understanding the distinct ways calcium channels and signaling regulate these processes may uncover potential targets for advancing biomaterials with regenerative osteogenic capabilities.

Association of Patient-Reported Anxiety and Pain After Alveolar Bone Grafting.

OBJECTIVE: To evaluate the role of psychosocial well-being on perioperative pain and opioid use among patients with cleft lip and palate (CLP) undergoing alveolar bone grafting (ABG). DESIGN: Retrospective review. SETTING: Tertiary level craniofacial clinic. PARTICIPANTS: 34 patients with CLP (median age: 11.7 years), including 25 (73.5%) unilateral CLP and 9 (26.5%) bilateral CLP, who underwent ABG from 2015 to 2022. INTERVENTIONS: ABG using iliac crest bone graft. Patients were prospectively administered four patient-reported psychosocial instruments from the Patient-Reported Outcomes Measurement Information System. MAIN OUTCOME MEASURES: Perioperative opioid use in morphine equivalent dosage/kilogram, patient-reported pain scores, and length of hospital stay after ABG. RESULTS: Patient-reported anxiety (r = 0.41, p = 0.02) and depressive symptoms (r = 0.35, p = 0.04) correlated to higher perioperative opioid usage. Multivariable regression models including psychosocial scores, total acetaminophen usage, length of surgery, and other simultaneous surgeries were developed for total opioid usage, patient-reported pain, and length of hospital stay. Patient-reported anxiety was independently predictive of higher perioperative opioid use (ß=0.36, p = 0.01) and higher pain scores (ß=0.39, p = 0.02), but not length of hospital stay. CONCLUSIONS: We identified an association for patient-reported anxiety and perioperative opioid use and pain in a CLP cohort undergoing ABG. Future considerations in preoperative patient and family consultation may be indicated in patients self-reporting higher anxiety in an effort to minimize perioperative opioid usage.

Modulating Temporospatial Phosphate Equilibrium by Nanoparticulate Mineralized Collagen Materials Induces Osteogenesis via PiT-1 and PiT-2.

The temporospatial equilibrium of phosphate contributes to physiological bone development and fracture healing, yet optimal control of phosphate content has not been explored in skeletal regenerative materials. Nanoparticulate mineralized collagen glycosaminoglycan (MC-GAG) is a synthetic, tunable material that promotes in vivo skull regeneration. In this work, the effects of MC-GAG phosphate content on the surrounding microenvironment and osteoprogenitor differentiation are investigated. This study finds that MC-GAG exhibits a temporal relationship with soluble phosphate with elution early in culture shifting to absorption with or without differentiating primary bone marrow-derived human mesenchymal stem cells (hMSCs). The intrinsic phosphate content of MC-GAG is sufficient to stimulate osteogenic differentiation of hMSCs in basal growth media without the addition of exogenous phosphate in a manner that can be severely reduced, but not eliminated, by knockdown of the sodium phosphate transporters PiT-1 or PiT-2. The contributions of PiT-1 and PiT-2 to MC-GAG-mediated osteogenesis are nonredundant but also nonadditive, suggestive that the heterodimeric form is essential to its activity. These findings indicate that the mineral content of MC-GAG alters phosphate concentrations within a local microenvironment resulting in osteogenic differentiation of progenitor cells via both PiT-1 and PiT-2.

Safety of Allogeneic Mesenchymal Stem Cell Seeding of NeuraGen Nerve Guides in a Rabbit Model.

Mesenchymal stem cells (MSCs) stimulate nerve and tissue regeneration and are primed for clinical translation. Application of autologous MSCs is limited by requirements for expedient harvesting procedures, proliferative expansion to increase number of cells, and reduced regenerative potential due to aging or pathological conditions. Because MSCs are immune privileged, allogeneic MSCs may serve as "off-the-shelf" cell-based reconstructive treatments to support nerve repair. Therefore, we examined the safety and immune response parameters of allogeneic MSCs seeded on NeuraGen® Nerve Guides (NNGs) in a rabbit model. NNGs with or without allogeneic rabbit MSCs were applied to rabbit sciatic nerves. Randomly assigned treatment included group I (no surgery control, n = 3) or groups II and III (sciatic nerve wrapped with unseeded or allogeneic MSC-seeded NNGs; n = 5/group). Rabbits were euthanized after 2 weeks to monitor functional recovery by histological evaluation of sciatic nerves and tibialis anterior (TA) muscle. Host reactions to allogeneic MSCs were analyzed by assessment of body and tissue weight, temperature, as well as hematological parameters, including white blood cell count (WBC), spleen histology, and CD4+ and CD8+ T lymphocytes. Histological analyses of nerves and spleen were all unremarkable, consistent with absence of overt systemic and local immune responses upon allogeneic MSC administration. No significant differences were observed in WBC or CD4+ and CD8+ T lymphocytes across unseeded and seeded treatment groups. Thus, allogenic MSCs are safe for use and may be considered in lieu of autologous MSCs in translational animal studies as the basis for future clinical nerve repair strategies. Impact statement Autologous mesenchymal stem cells (MSC) have been reported to enhance nerve regeneration when used in conjunction with nerve graft substitutes. However, autologous stem cell sources delay treatment and may be susceptible to age- or disease-related dysfunctions. In this study, we investigated the safety of allogeneic MSCs and the optimal number of cells for nerve conduit delivery in a rabbit model. When compared with unseeded nerve conduits, allogeneic MSC-seeded conduits did not induce a systemic or local immune response. The findings of this study will ultimately facilitate the clinical translation of a universal donor cell-based treatment option for nerve defects.

Osteoprotegerin-eluting nanoparticulate mineralized collagen scaffolds improve skull regeneration.

Custom synthesis of extracellular matrix (ECM)-inspired materials for condition-specific reconstruction has emerged as a potentially translatable regenerative strategy. In skull defect reconstruction, nanoparticulate mineralized collagen glycosaminoglycan scaffolds (MC-GAG) have demonstrated osteogenic and anti-osteoclastogenic properties, culminating in the ability to partially heal in vivo skull defects without the addition of exogenous growth factors or progenitor cell loading. In an effort to reduce catabolism during early skull regeneration, we fabricated a composite material (MCGO) of MC-GAG and recombinant osteoprotegerin (OPG), an endogenous anti-osteoclastogenic decoy receptor. In the presence of differentiating osteoprogenitors, MCGO demonstrated an additive effect with endogenous OPG limited to the first 14 days of culture with total eluted and scaffold-bound OPG exceeding that of MC-GAG. Functionally, MCGO exhibited similar osteogenic properties as MC-GAG, however, MCGO significantly reduced maturation and resorptive activities of primary human osteoclasts. In a rabbit skull defect model, MCGO scaffold-reconstructed defects displayed higher mineralization as well as increased hardness and microfracture resistance compared to non-OPG functionalized MC-GAG scaffolds. The current work suggests that MCGO is a development in the goal of reaching a materials-based strategy for skull regeneration.

COVID-19 Pandemic Associated With Increased Self-reported Depressive Symptoms in Patients With Congenital Craniofacial Diagnoses.

OBJECTIVE: The current study investigated the influence of the coronavirus (COVID-19) pandemic on patients with congenital craniofacial diagnoses. METHODS: Patients (n = 66) with craniofacial diagnoses aged between 8 and 17 were prospectively evaluated with longitudinal psychosocial assessments using the anger, anxiety, depressive symptoms, and peer relationships instruments within the pediatric Patient-Reported Outcomes Measurement Information System (PROMIS). The COVID-19 cohort (n = 33) included patients with assessments within 2 years prior to the pandemic (t0) and during the pandemic (t1; March 2020 to March 2021). An age-matched comparison cohort (n = 33) with similar demographics and diagnoses included patients assessed twice over 3 years prior to the pandemic. RESULTS: All PROMIS measures were in the average range clinically for both groups across time points. However, the COVID-19 group reported a significant increase in depressive symptoms during the pandemic (t1) compared to pre-pandemic (t0) scores (48.2 ± 10.1 vs 44.3 ± 9.4, P = .04, d = -0.37), while the comparison group did not demonstrate any differences in psychosocial functioning between t0 and t1. For the COVID-19 cohort, only the pandemic timeframe (r = 0.21, P = .03) was significantly associated with increased depressive symptom scores, and no other sociodemographic or medical variables were associated with depressive symptoms. CONCLUSIONS: Self-reported depressive symptoms increased during the COVID-19 pandemic in patients with congenital craniofacial diagnoses. Longitudinal studies are needed to elucidate whether such changes will be persistent or compound known variables associated with psychosocial functioning.

Dynamic seeding versus microinjection of mesenchymal stem cells for acellular nerve allograft: an in vitro comparison.

BACKGROUND: Mesenchymal stem cell (MSC)-supplemented acellular nerve allografts (ANA) are a potential strategy to improve the treatment of segmental nerve defects. Prior to clinical translation, optimal cell delivery methods must be defined. While two techniques, dynamic seeding and microinjection, have been described, the seeding efficiency, cell viability, and distribution of MSCs in ANAs are yet to be compared. METHODS: Sciatic nerve segments of Sprague-Dawley rats were decellularized, and MSCs were harvested from the adipose tissue of Lewis rats. Cell viability was evaluated after injection of MSCs through a 27-gauge needle at different flow rates (10, 5, and 1 µL/min). MSCs were dynamically seeded or longitudinally injected into ANAs. Cell viability, seeding efficiency, and distribution were evaluated using LIVE/DEAD and MTS assays, scanning electron microscopy, and Hoechst staining. RESULTS: No statistically significant difference in cell viability after injection at different flow rates was seen. After cell delivery, 84.1 ± 3.7% and 87.8 ± 2.8% of MSCs remained viable in the dynamic seeding and microinjection group, respectively (p = 0.41). The seeding efficiency of microinjection (100.4%±5.6) was significantly higher than dynamic seeding (48.1%±8.6) on day 1 (p = 0.001). Dynamic seeding demonstrated a significantly more uniform cell distribution over the course of the ANA compared to microinjection (p = 0.02). CONCLUSION: MSCs remain viable after both dynamic seeding and microinjection in ANAs. Higher seeding efficiency was observed with microinjection, but dynamic seeding resulted in a more uniform distribution. In vivo studies are required to assess the effect on gene expression profiles and functional motor outcomes.