Auricular growth potential of patients with concha-type microtia after auricular cartilage stretching surgery: A prospective study.

BACKGROUNDS: For patients with concha-type microtia, surgical intervention and the degree of deformity may affect the growth rate of the auricular cartilage, which is different at different ages. This study aimed to explore the auricular growth potential of patients with concha-type microtia at different ages after auricular cartilage stretching surgery. METHODS: A total of 66 patients with unilateral grade II and III concha-type microtia were involved in this prospective cohort study. All patients underwent auricular cartilage stretching surgery. Relevant data were collected before surgery, immediately after surgery, and at the last follow-up. RESULTS: The perimeter, width, and length of auricle, between each follow-up, was statistically significant, which supported the effect of surgery and auricular development. For patients in the grade II group, no statistical significance was found in the difference in the perimeter, width, and length between the affected and normal auricle. For the patients in the grade III group, the difference in the relevant indexes of the affected auricle was significantly different from those of the normal auricle. Between subgroups divided according to their age, the growth potential of affected auricle with the same degree of deformity was statistically significant. CONCLUSIONS: Growth potential of the affected auricle of the grade II group was consistent with that of the normal auricle, which was significantly higher than that of the grade III group. For patients at different ages, auricles grew faster before 3 years of age. Surgical intervention improved the auricular aesthetics and released the auricular growth potential. Thus, surgical intervention should be recommend as early as possible.

A new corrective method for the Tanzer's group IIB constricted ear: Helical expansion using V-Y advancement flap combined with concha cartilage graft.

BACKGROUND: The complexity of a constricted ear shape renders the aim of establishing a uniform surgical method unattainable, thus posing an ongoing challenge in its correction. The Tanzer's group IIB constricted ear is characterized by a prominent downward folding, an underdeveloped antihelix, and the absence of sacpha. The present study used a V-Y advancement flap combined with concha cartilage for the repair of Tanzer's group IIB constricted ear. METHOD: A total of 16 patients diagnosed with type IIB ear constriction from September 2016 to September 2022 were enrolled in this retrospective study. The correction procedure for the constricted ear involved the utilization of a V-Y advancement flap combined with concha cartilage graft. The auricle shape data of the patients, their visual analog scale (VAS) satisfaction scores, and aesthetic outcomes scale (AOS) aesthetic scores were examined preoperatively and 12 months post-operatively. RESULT: The mean duration of follow-up in this study was 18 months. The post-operative measurements of ear length, ear width, bilateral differences in ear length, and bilateral differences in ear width exhibited significant improvement compared to the preoperative values. The mean preoperative AOS score was 1.12 ± 0.34, and the mean post-operative AOS score increased to 3.81 ± 0.40. The preoperative VAS satisfaction score was 2.31 ± 0.70, whereas the post-operative VAS score significantly increased to 8.00 ± 0.89. The follow-up period did not present any cases of flap necrosis, hematoma, infection, or wound dehiscence. CONCLUSION: The combination of V-Y advancement flap and concha cartilage transplantation for the correction of Tanzer's group IIB constricted ear can achieve a natural and aesthetically pleasing auricle shape, resulting in high patient satisfaction.

Single-stage reconstruction of severe question mark ear with the absence of large portions of the lobule using affected cartilage graft and 3 flaps.

BACKGROUND: Question mark ear (QME) is a congenital abnormality characterized by a prominent curve within the helix that resembles a question mark. Several surgical reconstruction techniques have been proposed to treat this deformity. In this study, we aimed to evaluate the cosmetic outcomes of a new cartilage and postauricular flap surgical reconstruction technique for patients diagnosed with severe QME. METHOD: From 2017 to 2023, 33 patients with severe QMEs were treated with a new reconstruction surgical technique at the Plastic Surgery Hospital of Peking Union Medical College. The perimeter, width, length, and auriculocephalic angles of both ears were measured and compared to assess the symmetry. The patient's satisfaction with the surgical outcomes and incidence of post-operative complications were also evaluated. The average follow-up duration was 15.48 months. RESULTS: The auricular perimeter, width, and length changed significantly after surgery. The dimensions of the left and right ear did not vary significantly in patients with unilateral or bilateral severe QME after surgery and at the end of the 1-year follow-up. Most patients (87.88%) or carers were satisfied with the cosmetic outcomes after surgery. All patients underwent suture removal 14 days after surgery and exhibited excellent wound healing without any complications such as hematoma, infection, and flap necrosis. CONCLUSION: Our new surgical reconstruction technique for severe QME resulted in good cosmetic outcomes, high patient satisfaction, fast recovery, and no post-operative complications.

Decreased Tiam1-mediated Rac1 activation is responsible for impaired directional persistence of chondrocyte migration in microtia.

The human auricle has a complex structure, and microtia is a congenital malformation characterized by decreased size and loss of elaborate structure in the affected ear with a high incidence. Our previous studies suggest that inadequate cell migration is the primary cytological basis for the pathogenesis of microtia, however, the underlying mechanism is unclear. Here, we further demonstrate that microtia chondrocytes show a decreased directional persistence during cell migration. Directional persistence can define a leading edge associated with oriented movement, and any mistakes would affect cell function and tissue morphology. By the screening of motility-related genes and subsequent confirmations, active Rac1 (Rac1-GTP) is identified to be critical for the impaired directional persistence of microtia chondrocytes migration. Moreover, Rho guanine nucleotide exchange factors (GEFs) and Rho GTPase-activating proteins (GAPs) are detected, and overexpression of Tiam1 significantly upregulates the level of Rac1-GTP and improves directional migration in microtia chondrocytes. Consistently, decreased expression patterns of Tiam1 and active Rac1 are found in microtia mouse models, Bmp5se/J and Prkralear-3J/GrsrJ. Collectively, our results provide new insights into microtia development and therapeutic strategies of tissue engineering for microtia patients.

Minimally Invasive Costal Cartilage Harvesting Incision for Chest Deformity in Microtia Reconstruction.

BACKGROUND: Chest deformity is a potential complication associated with auricular reconstruction using autologous costal cartilage. The impact of the incision size employed for costal cartilage harvesting on chest deformities remains unclear. This study aimed to investigate the correlation between the incision size used for harvesting costal cartilage and the occurrence of chest deformities. METHODS: We retrospectively analyzed patients who underwent ear reconstruction using autologous costal cartilage between June 2021 and September 2022. The patients were categorized into two groups based on the size of the costal cartilage incision: large and small. Chest computed tomography (CT) was performed 18-24 months postoperatively, followed by three-dimensional color map quantification to assess the degree of asymmetry of the chest surface. Subsequently, quantitative data analysis was performed to compare the extent of chest asymmetry between the large- and small-incision groups. The Visual Analog Scale (VAS) was used to assess patient satisfaction with chest morphology. RESULTS: This study included 62 patients, with an equal distribution of 31 in each group. The mean asymmetry value of the small and large incision groups was -3.15 ± 1.88 and -5.27 ± 3.63, respectively. Moreover, the mean VAS score for the small and large incision groups was 7.48 ± 0.72 and 5.09 ± 0.94, respectively. Statistically significant differences were observed between the two groups. CONCLUSIONS: Small incision costal cartilage harvesting can effectively alleviate the severity of chest deformities and significantly enhance patient satisfaction. 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 .

A quick and innovative pipeline for producing chondrocyte-homing peptide-modified extracellular vesicles by three-dimensional dynamic culture of hADSCs spheroids to modulate the fate of remaining ear chondrocytes in the M1 macrophage-infiltrated microenvironment.

BACKGROUND: Extracellular vesicles (EVs) derived from human adipose-derived mesenchymal stem cells (hADSCs) have shown great therapeutic potential in plastic and reconstructive surgery. However, the limited production and functional molecule loading of EVs hinder their clinical translation. Traditional two-dimensional culture of hADSCs results in stemness loss and cellular senescence, which is unfavorable for the production and functional molecule loading of EVs. Recent advances in regenerative medicine advocate for the use of three-dimensional culture of hADSCs to produce EVs, as it more accurately simulates their physiological state. Moreover, the successful application of EVs in tissue engineering relies on the targeted delivery of EVs to cells within biomaterial scaffolds. METHODS AND RESULTS: The hADSCs spheroids and hADSCs gelatin methacrylate (GelMA) microspheres are utilized to produce three-dimensional cultured EVs, corresponding to hADSCs spheroids-EVs and hADSCs microspheres-EVs respectively. hADSCs spheroids-EVs demonstrate excellent production and functional molecule loading compared with hADSCs microspheres-EVs. The upregulation of eight miRNAs (i.e. hsa-miR-486-5p, hsa-miR-423-5p, hsa-miR-92a-3p, hsa-miR-122-5p, hsa-miR-223-3p, hsa-miR-320a, hsa-miR-126-3p, and hsa-miR-25-3p) and the downregulation of hsa-miR-146b-5p within hADSCs spheroids-EVs show the potential of improving the fate of remaining ear chondrocytes and promoting cartilage formation probably through integrated regulatory mechanisms. Additionally, a quick and innovative pipeline is developed for isolating chondrocyte homing peptide-modified EVs (CHP-EVs) from three-dimensional dynamic cultures of hADSCs spheroids. CHP-EVs are produced by genetically fusing a CHP at the N-terminus of the exosomal surface protein LAMP2B. The CHP + LAMP2B-transfected hADSCs spheroids were cultured with wave motion to promote the secretion of CHP-EVs. A harvesting method is used to enable the time-dependent collection of CHP-EVs. The pipeline is easy to set up and quick to use for the isolation of CHP-EVs. Compared with nontagged EVs, CHP-EVs penetrate the biomaterial scaffolds and specifically deliver the therapeutic miRNAs to the remaining ear chondrocytes. Functionally, CHP-EVs show a major effect on promoting cell proliferation, reducing cell apoptosis and enhancing cartilage formation in remaining ear chondrocytes in the M1 macrophage-infiltrated microenvironment. CONCLUSIONS: In summary, an innovative pipeline is developed to obtain CHP-EVs from three-dimensional dynamic culture of hADSCs spheroids. This pipeline can be customized to increase EVs production and functional molecule loading, which meets the requirements for regulating remaining ear chondrocyte fate in the M1 macrophage-infiltrated microenvironment.

The impact of national health insurance on the cost of auricular reconstruction with skin expansion for microtia in China: A single-center retrospective study based on 1290 surgeries.

BACKGROUND: Congenital microtia presents challenges that encompass physical disabilities and psychosocial distress. It is reported that people with low income have a higher possibility of giving birth to babies with congenital malformations. At the end of June 2023, auricular reconstruction was partially incorporated into national health insurance in our hospital. METHODS: Briefly, 1290 surgeries, including stage-I and stage-II auricular reconstruction with tissue expansion were performed in 2023, involving 779 patients. Patient data, including age, sex, length of stay, residence, and costs, were retrieved from the electronic medical record system. The final cost before and after health insurance coverage, as well as the medical insurance reimbursement ratio in each province and municipality were statistically analyzed. RESULTS: Following insurance coverage, a significant increase in the number of surgeries was observed (514 [39.84%] vs. 776 [60.16%], χ2 = 45.99, p = 0.000), with notable reductions in out-of-pocket costs for unilateral and bilateral stage-I and -II auricular reconstructions ($3915.01 vs. $6645.28, p < 0.05; $11546.80 vs. $5198.08, p < 0.05). Disparities in reimbursement rates across regions were evident, but showed no correlation to the local GDP per capita. There was a positive correlation between the length of stay and inpatient cost. Patient's age was not related to the inpatient cost, but to the length of stay. CONCLUSION: The health insurance coverage for microtia treatment significantly alleviated financial burdens on the patients' family and increased the number of auricular reconstruction surgeries. These findings underscore the critical role of insurance coverage in enhancing healthcare accessibility and affordability for patients with congenital microtia.

Assessment of the 2023 ACR/EULAR antiphospholipid syndrome classification criteria in a Chinese cohort: Impact on clinical practice.

OBJECTIVES: To evaluate the effectiveness of the 2023 ACR/EULAR criteria for antiphospholipid syndrome (APS) in a Chinese cohort, and compare them with the Sapporo and revised Sapporo criteria. METHODS: A cohort comprising 436 patients diagnosed with APS and 514 control subjects was enrolled, including 83 with seronegative APS and 86 classified as antiphospholipid antibody (aPL) carriers. We assessed IgG and IgM anticardiolipin antibodies (aCL) and anti-ß2-glycoprotein I (aß2GPI) antibodies using ELISA, along with a systematic collection of lupus anticoagulant data. Subsequently, we compared the sensitivity and specificity across the three classification criteria. RESULTS: The 2023 ACR/EULAR criteria exhibited improved specificity at 98 %, surpassing the revised Sapporo (90 %) and original Sapporo (91 %) criteria. However, this came with decreased sensitivity at 82 %, in contrast to higher sensitivities in the revised Sapporo (98 %) and Sapporo (91 %) criteria. Examining individual components sheds light on the scoring system's rationale within the new criteria. The inclusion of microvascular thrombosis, cardiac valve disease, and thrombocytopenia improved the identification of nine patients previously classified as "probable APS". Insufficient scoring in 78 previously diagnosed APS individuals was linked to traditional risk factor evaluations for thrombotic events, the emphasis on determining whether obstetric events are linked to severe preeclampsia (PEC) or placental insufficiency (PI), and the lower scores assigned to IgM aCL and/or aß2GPI antibody. Seronegative APS remained a challenge, as non-criteria aPL and other methods were not included. CONCLUSIONS: The new criteria presented notable advancements in specificity. This study provides detailed insights into the strengths and possible challenges of the 2023 ACR/EULAR criteria, enhancing our understanding of their impact on clinical practice.

New Method Using Local Affected Cartilage and Flap for the Cleft in Question Mark Ear.

BACKGROUND: As a rare auricular deformity, despite numerous surgical procedures for correcting moderate-to-severe question mark ears described in past studies, there remains a need to explore a more cost-effective approach. The optimal utilization of ear cartilage and surrounding skin while achieving superior outcomes continues to pose a significant challenge. METHODS: From 2018 to 2023, twenty-four patients with unilateral question mark ear were enrolled in this study. Seven of them were severe type deformities (absence of lower part of auricle), and seventeen were moderate (only cleft between helix and lobule). All patients were treated with new method using local cartilage and flap without damage in unaffected area. RESULTS: All patients were satisfied with significant improvement of question mark ear and the overall symmetrical appearance. The surgical scar was not obvious. No complications were observed. The follow-up period revealed that the corrective procedure kept producing the symmetrical and cosmetic results. CONCLUSION: Our new method enables optimal utilization of deformed tissue and surrounding skin, rendering this method effective and reliable for correcting moderate-to-severe question mark ears. 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 .

Glycopeptide-based multifunctional nanofibrous hydrogel that facilitates the healing of diabetic wounds infected with methicillin-resistant Staphylococcus aureus.

Diabetic wound management remains a significant challenge in clinical care due to bacterial infections, excessive inflammation, presence of excessive reactive oxygen species (ROS), and impaired angiogenesis. The use of multifunctional wound dressings has several advantages in diabetic wound healing. Moreover, the balance of macrophage polarization plays a crucial role in promoting skin regeneration. However, few studies have focused on the development of multifunctional wound dressings that can regulate the inflammatory microenvironment and promote diabetic wound healing. In this study, an extracellular matrix-inspired glycopeptide hydrogel composed of glucomannan and polypeptide was proposed for regulating the local microenvironment of diabetic wound sites. The hydrogel network, which was formed via Schiff base and hydrogen bonding interactions, effectively inhibited inflammation and promoted angiogenesis during wound healing. The hydrogels exhibited sufficient self-healing ability and had the potential to scavenge ROS and to activate the mannose receptor (MR), thereby inducing macrophage polarization toward the M2 phenotype. The experimental results confirm that the glycopeptide hydrogel is an effective tool for managing diabetic wounds by showing antibacterial, ROS scavenging, and anti-inflammatory effects, and promoting angiogenesis to facilitate wound repair and skin regeneration in vivo. STATEMENT OF SIGNIFICANCE: •The designed wound dressing combines the advantage of natural polysaccharide and polypeptide. •The hydrogel promotes M2-polarized macrophages, antibacterial, scavenges ROS, and angiogenesis. •The multifunctional glycopeptide hydrogel dressing could accelerating diabetic wound healing in vivo.

Co-culture of RhoA-overexpressed microtia chondrocytes and adipose-derived stem cells in the construction of tissue-engineered ear-shaped cartilage.

Microtia is a congenital auricle dysplasia with a high incidence and tissue engineering technology provides a promising strategy to reconstruct auricles. We previously described that the engineered cartilage constructed from microtia chondrocytes exhibited inferior levels of biochemical and biomechanical properties, which was proposed to be resulted of the decreased migration ability of microtia chondrocytes. In the current study, we found that Rho GTPase members were deficient in microtia chondrocytes. By overexpressing RhoA, Rac1, and CDC42, respectively, we further demonstrated that RhoA took great responsibility for the decreased migration ability of microtia chondrocytes. Moreover, we constructed PGA/PLA scaffold-based cartilages to verify the chondrogenic ability of RhoA overexpressed microtia chondrocytes, and the results showed that overexpressing RhoA was of limited help in improving the quality of microtia chondrocyte engineered cartilage. However, coculture of adipose-derived stem cells (ADSCs) significantly improved the biochemical and biomechanical properties of engineered cartilage. Especially, coculture of RhoA overexpressed microtia chondrocytes and ADSCs produced an excellent effect on the wet weight, cartilage-specific extracellular matrix, and biomechanical property of engineered cartilage. Furthermore, we presented that coculture of RhoA overexpressed microtia chondrocytes and ADSCs combined with human ear-shaped PGA/PLA scaffold and titanium alloy stent fabricated by CAD/CAM and 3D printing technology effectively constructed and maintained auricle structure in vivo. Collectively, our results provide evidence for the essential role of RhoA in microtia chondrocytes and a developed strategy for the construction of patient-specific tissue-engineered auricular cartilage.

Relocation of polyotia tissue to reconstruct the tragus and fill the preauricular depression.

OBJECTIVES: The present article introduces a lingual composite tissue flap based on the tragus-like structure for correcting polyotia deformity, with the aim of providing a surgical technique that involves relocating polyotia tissue to reconstruct the tragus and fill the preauricular depression. METHODS: The study included a total of 21 patients with polyotia who underwent lingual composite tissue flap reconstruction between January 2020 to December 2022. Patients were retrospectively assessed through a comprehensive review of their medical records and photographic data. Tragus morphology was evaluated based on the measurements of tragus length and width. The Aesthetic Outcomes Scale (AOS), modified Vancouver Scar Scale (mVSS), and Visual Analogue Scale (VAS) were employed for the assessment of surgical outcomes. RESULTS: The follow-up period for all patients ranged from 6 to 15 months. The length and width of the normal tragus were not significantly different from those of the reconstructed tragus. The mean preoperative AOS score was 2.73 ± 0.51, while the mean postoperative AOS score increased to 7.61 ± 0.65. The mVSS yielded an average score of 1.80 ± 1.43, indicating inconspicuous scarring post polyotia surgery. The preoperative VAS satisfaction score was recorded as 1.57 ± 0.67, while the postoperative VAS score significantly increased to 8.33 ± 0.91. The flaps all successfully survived post-operation without any occurrences of flap hematoma, necrosis, infection, or wound dehiscence. CONCLUSION: The reconstruction of the tragus should be given careful consideration when addressing polyotia. The utilization of a lingual composite tissue flap for correction can achieve excellent aesthetic results for the tragus, with high patient satisfaction and minimal complications.

Retrospective study on unilateral polyotia combined with microtia utilizing the technique of preserving residual ear tissue.

BACKGROUND: The presence of polyotia in individuals with microtia is a rare deformity. Due to the intricate structure of the auricle, uncertain etiology, and challenging corrective techniques, it has always been a focal point in the field of plastic surgery. The present study presents a technique for correcting the combination of polyotia and microtia by utilizing residual ear tissue as graft material. METHODS: The retrospective study included 23 patients with polyotia and microtia from 2018 to 2022. The residual ear tissue was used to rectify auricular deformities in all patients. The patients were instructed to evaluate the satisfaction of the auricle shape using a visual analog scale (VAS) both before and 6 months after the surgical procedure. The esthetic outcomes of auricle subunits were simultaneously assessed by a senior physician pre- and postoperatively. RESULTS: The mean duration of follow-up in this study was 8.73 months. The preoperative VAS satisfaction score was recorded as 2.26 ± 0.86, while the post-operative VAS score significantly increased to 7.86 ± 0.86. The preoperative auricle esthetic outcomes score was recorded as 9.95 ± 1.74, while the post-operative score significantly increased to 24.04 ± 2.16. The follow-up period did not present any cases of flap necrosis, hematoma, infection, or wound dehiscence. CONCLUSION: The study demonstrates that comprehensive utilization of residual auricular tissue can lead to optimal outcomes in correcting polyotia with concha-type microtia. The utilization of residual ear tissue can be maximized to streamline the operation, minimize bodily harm, and enhance patient satisfaction.

Engineered hsa-miR-455-3p-Abundant Extracellular Vesicles Derived from 3D-Cultured Adipose Mesenchymal Stem Cells for Tissue-Engineering Hyaline Cartilage Regeneration.

Efforts are made to enhance the inherent potential of extracellular vesicles (EVs) by utilizing 3D culture platforms and engineered strategies for functional cargo-loading. Three distinct types of adipose mesenchymal stem cells-derived EVs (ADSCs-EVs) are successfully isolated utilizing 3D culture platforms consisting of porous gelatin methacryloyl (PG), PG combined with sericin methacryloyl (PG/SerMA), or PG combined with chondroitin sulfate methacryloyl (PG/ChSMA). These correspond to PG-EVs, PG/SerMA-EVs, and PG/ChSMA-EVs, respectively. Unique microRNA (miRNA) profiles are observed in each type of ADSCs-EVs. Notably, PG-EVs encapsulate higher levels of hsa-miR-455-3p and deliver more hsa-miR-455-3p to chondrocytes, which results in the activation of the hsa-miR-455-3p/PAK2/Smad2/3 axis and the subsequent hyaline cartilage regeneration. Furthermore, the functionality of PG-EVs is optimized through engineered strategies, including agomir/lentivirus transfection, electroporation, and Exo-Fect transfection. These strategies, referred to as Agomir-EVs, Lentivirus-EVs, Electroporation-EVs, and Exo-Fect-EVs, respectively, are ranked based on their efficacy in encapsulating hsa-miR-455-3p, delivering hsa-miR-455-3p to chondrocytes, and promoting cartilage formation via the hsa-miR-455-3p/PAK2/Smad2/3 axis. Notably, Exo-Fect-EVs exhibit the highest efficiency. Collectively, the 3D culture conditions and engineered strategies have an impact on the miRNA profiles and cartilage regeneration capabilities of ADSCs-EVs. The findings provide valuable insights into the mechanisms underlying the promotion of cartilage regeneration by ADSCs-EVs.

Prograde transposition for anteriorly low-set earlobe in lobule-type microtia reconstruction.

BACKGROUND: Lobule transposition, a common procedure in auricle reconstruction, has been successfully performed over the past few decades. However, the transposition methods for unilateral microtia with evident asymmetry of bilateral earlobe positions still remain a challenge. The objective of this study was to investigate the application of prograde transposition for anteriorly low-set earlobes. METHOD: A total of 25 patients with lobule-type microtia with anteriorly low-set residual earlobe underwent prograde transposition during auricle reconstruction between 2020 and 2022. The post-operative earlobe aesthetic assessment and patient satisfaction were evaluated, and the data on any complications that occurred when followed-up were collected. This study provides a comprehensive analysis and summary of the techniques used in earlobe transposition for auricular reconstruction. RESULTS: The patients with evident asymmetry between the residual and healthy earlobes were usually concomitant with hemifacial microsomia and the residual ear was located in the anterior and lower region. No instances of flap necrosis, hematoma, or wound dehiscence were observed following auricular reconstruction. The mean aesthetic score of the auricle was 3.52, with 23 patients attaining good or excellent aesthetic outcomes. The mean Visual Analog Scale satisfaction score was 3.68, with 24 patients reporting relative satisfaction or satisfaction. CONCLUSION: The prograde transposition of anteriorly low-set earlobe in lobule-type microtia reconstruction can effectively ensure adequate blood supply, enhance aesthetic appearance, and significantly improve patient satisfaction.

Low-Temperature Extrusion of Waterborne Polyurethane-Polycaprolactone Composites for Multi-Material Bioprinting of Engineered Elastic Cartilage.

3D bioprinting of elastic cartilage tissues that are mechanically and structurally comparable to their native counterparts, while exhibiting favorable cellular behavior, is an unmet challenge. A practical solution for this problem is the multi-material bioprinting of thermoplastic polymers and cell-laden hydrogels using multiple nozzles. However, the processing of thermoplastic polymers requires high temperatures, which can damage hydrogel-encapsulated cells. In this study, the authors developed waterborne polyurethane (WPU)-polycaprolactone (PCL) composites to allow multi-material co-printing with cell-laden gelatin methacryloyl (GelMA) hydrogels. These composites can be extruded at low temperatures (50-60 °C) and high speeds, thereby reducing heat/shear damage to the printed hydrogel-capsulated cells. Furthermore, their hydrophilic nature improved the cell behavior in vitro. More importantly, the bioprinted structures exhibited good stiffness and viscoelasticity compared to native elastic cartilage. In summary, this study demonstrated low-temperature multi-material bioprinting of WPU-PCL-based constructs with good mechanical properties, degradation time-frames, and cell viability, showcasing their potential in elastic cartilage bio-fabrication and regeneration to serve broad biomedical applications in the future.

The Effects of Radial Cartilage Incision on the Growth of Rabbit Ear.

OBJECTIVES: Recently, radial cartilage incision (first-stage) at an early age combined with free auricular composite tissue grafting (second-stage) can effectively correct the concha-type microtia with the moderate or severe folded cartilage in the middle and upper third auricle, but radial cartilage incision's effects on the growth of the ear remain to be determined. The authors aimed to evaluate the effects of radial cartilage incision in young rabbits model. METHODS: Ten New Zealand white rabbits were included in our experiment. Two ears of each rabbit were divided randomly into two groups. The experimental group was operated with radial cartilage incision, and no intervention was given to the control group. The ear width, length, and perimeter were noted every two weeks. Auricular surface area was noted at 4 and 22 weeks old. The repeated measures ANOVA was used to describe ears' growth trend. A paired-sample's t test is conducted to test whether there are significant differences among the variables through the SPSS25.0 software. RESULTS: The growth tendencies of the ear length, width, and perimeter were observed and analyzed. The growth curves of the experimental ears were similar to that of the control. There was no significant difference in the increased ratio of surface area among the two groups. The cartilage of the experimental ears showed no change in biomechanical properties compared to that of control group. CONCLUSION: This study shows that radial cartilage incision at an early age does not influence the growth of rabbit ear length, width, perimeter, and surface area and also does not change the biomechanical properties of the cartilage. LEVEL OF EVIDENCE I: 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 .

Photo-induced universal modification of small-diameter decellularized blood vessels with a hemocompatible peptide improves in vivo patency.

Decellularized vessels (DVs) have the potential to serve as available grafts for small-diameter vascular (<6 mm) reconstruction. However, the absence of functional endothelia makes them likely to trigger platelet aggregation and thrombosis. Luminal surface modification is an efficient approach to prevent thrombosis and promote endothelialization. Previously, we identified a hemocompatible peptide, HGGVRLY, that showed endothelial affinity and antiplatelet ability. By conjugating HGGVRLY with a phenylazide group, we generated a photoreactive peptide that can be modified onto multiple materials, including non-denatured extracellular matrices. To preserve the natural collagen of DVs as much as possible, we used a lower ultrahydrostatic pressure than that previously reported to prepare decellularized grafts. The photoreactive HGGVRLY peptide could be modified onto DV grafts via UV exposure for only 2 min. Modified DVs showed improved endothelial affinity and antiplatelet ability in vitro. When rat abdominal aortas were replaced with DVs, modified DVs with more natural collagen demonstrated the highest patent rate after 10 weeks. Moreover, the photoreactive peptide remained on the lumen surface of DVs over two months after implantation. Therefore, the photoreactive peptide could be efficiently and sustainably modified onto DVs with more natural collagens, resulting in improved hemocompatibility. STATEMENT OF SIGNIFICANCE: We employed a relatively lower ultrahydrostatic pressure to prepare decellularized vessels (DVs) with less denatured collagens to provide a more favorable environment for cell migration and proliferation. The hemocompatibility of DV luminal surface can be enhanced by peptide modification, but undenatured collagens are difficult to modify. We innovatively introduce a phenylazide group into the hemocompatible peptide HGGVRLY, which we previously identified to possess endothelial affinity and antiplatelet ability, to generate a photoreactive peptide. The photoreactive peptide can be efficiently and stably modified onto DVs with more natural collagens. DV grafts modified with photoreactive peptide exhibit enhanced in vivo patency. Furthermore, the sustainability of photoreactive peptide modification on DV grafts within bloodstream is evident after two months of transplantation.

Correlations Among Clinical Phenotypes, Radiological Examination Indexes, and Hearing Status in Congenital Microtia.

Microtia is a congenital malformation of the external ear that often presents with other anatomical abnormalities and ipsilateral hearing loss (HL). The aim of this study was to present the correlation among important phenotypic abnormalities in microtia and their relationship with HL in a clinical population in China. In this study, a retrospective analysis was conducted on 307 patients diagnosed with microtia who visited the Department of Auricular Reconstruction of the Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, for surgical auricle reconstruction from April 2021 to April 2022. Standardized classification of ear malformations, craniofacial CT scans, and pure tone audiometric data were collected, and statistical analyses were performed using the rank sum test, Kruskal-Wallis test, and Spearman's rank correlation coefficient. The results showed that group differences between ear malformation and variations in the development of mandible, external auditory canal (EAC), and mastoid pneumatization were statistically significant and each had a positive correlation. Among them, the correlation between development of ear and EAC was the most significant (Ρ=0.72). Besides, the severity of HL (97% were conductive) was positively correlated with ear and EAC dysplasia with or without mandibular hypoplasia. Based on the statistical analysis of the correlation between ear malformation and HL, the authors strongly recommend that facial phenotype reconstruction and hearing improvement of microtia should be considered comprehensively, regardless of whether children with microtia show HL or not, early diagnosis of audiology evaluation and appropriate intervention measures should be implemented.

Peelable Microneedle Patches Deliver Fibroblast Growth Factors to Repair Skin Photoaging Damage.

Rationale: UV light deeply penetrates the dermis, leading to inflammation and cell death with prolonged exposure. This is a major contributor to skin photoaging. In the pharmaceutical field, fibroblast growth factors (FGFs) have gained popularity for enhancing skin quality as they facilitate tissue remodeling and re-epithelization. Nonetheless, their effectiveness is significantly hindered by limited absorption. Methods: We have successfully created a dissolving microneedle (MN) patch that contains hyaluronic acid (HA) loaded with FGF-2 and FGF-21. This patch aims to improve the therapeutic efficiency of these growth factors while providing a simple administration method. We determined the performance of this patch in an animal model of skin photoaging. Results: The FGF-2/FGF-21-loaded MN (FGF-2/FGF-21 MN) patch demonstrated a consistent structure and suitable mechanical properties, allowing for easy insertion and penetration into mouse skin. Within 10 minutes of application, the patch released approximately 38.50 ± 13.38% of the loaded drug. Notably, the FGF-2/FGF-21 MNs exhibited significant improvements in UV-induced acute skin inflammation and reduced mouse skin wrinkles within a span of two weeks. Furthermore, the positive effects continued to enhance over a four-week treatment period. Conclusion: The proposed HA-based peelable MN patch provides an efficient approach for transdermal drug delivery, providing a promising method for improved therapeutic outcomes.