The Evolution of Microfluidic-Based Drug-Loading Techniques for Cells and Their Derivatives.

Conventional drug delivery techniques face challenges related to targeting and adverse reactions. Recent years have witnessed significant advancements in nanoparticle-based drug carriers. Nevertheless, concerns persist regarding their safety and insufficient metabolism. Employing cells and their derivatives, such as cell membranes and extracellular vesicles (EVs), as drug carriers effectively addresses the challenges associated with nanoparticle carriers. However, an essential hurdle remains in efficiently loading drugs into these carriers. With the advancement of microfluidic technology and its advantages in precise manipulation at the micro- and nanoscales, as well as minimal sample loss, it has found extensive application in the loading of drugs using cells and their derivatives, thereby fostering the development of drug-loading techniques. This paper outlines the characteristics and benefits of utilizing cells and their derivatives as drug carriers and provides an overview of current drug-loading techniques, particularly those rooted in microfluidic technology. The significant potential for microfluidic technology in targeted disease therapy through drug delivery systems employing cells and their derivatives, is foreseen.

A Carbon-Caged Rhodamine Generating Nitrosoperoxycarbonate for Photoimmunotherapy.

Photoimmunotherapy is a promising cancer treatment modality. While potent 1-e- oxidative species are known to induce immunogenic cell death (ICD), they are also associated with unspecific oxidation and collateral tissue damage. This difficulty may be addressed by post-generation radical reinforcement. Namely, non-oxidative radicals are first generated and subsequently activated into powerful oxidative radicals to induce ICD. Here, we developed a photo-triggered molecular donor (NPCD565) of nitrosoperoxycarbonate (ONOOCO2 -), the first of its class to our knowledge, and further evaluated its feasibility for immunotherapy. Upon irradiation of NPCD565 by light within a broad spectral region from ultraviolet to red, ONOOCO2 - is released along with a bright rhodamine dye (RD565), whose fluorescence is a reliable and convenient build-in reporter for the localization, kinetics, and dose of ONOOCO2 - generation. Upon photolysis of NPCD565 in 4T1 cells, damage-associated molecular patterns (DAMPs) indicative of ICD were observed and confirmed to exhibit immunogenicity by induced maturation of dendritic cells. In vivo studies with a bilateral tumor-bearing mouse model showcased the potent tumor-killing capability of NPCD565 of the primary tumors and growth suppression of the distant tumors. This work unveils the potent immunogenicity of ONOOCO2 -, and its donor (NPCD565) has broad potential for photo-immunotherapy of cancer.

Validation and efficacy of 'pure' venous lymph node flap in a rat lymphoedema model.

The venous lymph node flap (vLNF) is regarded as an arterialized or 'pure' venous flap, subject to which type of vessel provides blood supply to the flap. However, whether the vLNF drainage function is maintainable or sufficient for the treatment of lymphoedema is yet to be elucidated. In this study, the venous flow-through lymph node flaps or 'pure' vLNF was investigated in a rat's tail (lymphoedema model), and the therapeutic effect was analysed to clarify its potential value for the treatment of lymphoedema. The subjects (rats) were divided into three groups, the experimental group ('pure' vLNF group), the control group (lymphoedema group), and the baseline group. The tail circumference and diameter were recorded for 5 weeks after the operation. Five weeks after surgery, the lymphatic drainage function was evaluated using indocyanine green (ICG) lymphography, while the skin thickness and collagen layer were assessed by histological analysis. The average diameter and circumference of the experimental group were significantly shorter than the control group (p < 0.01). When comparing ICG lymphography within the three groups, the baseline group showed that the ICG entered the inguinal lymph node and appeared in the liver while the ICG still accumulated in the oedematous tail with no fluorescence emerging in other parts of the rat's body, in the control group. In the experimental group, the ICG entered the vLNF via the flap junction with the rat's tail and fluorescence emerging in the rat's liver. When comparing the three groups above with the control group, the experimental group's skin and collagen layer thickness were significantly improved (p < 0.01). Lymphatic recanalization was shown to appear between 'pure' vLNF and the recipient area. Moreover, vLNF was shown to drain lymph fluid via the venous system, thus relieved swelling and fibrosis of the lymphoedematous tissue. Consequently, this could represent a new potential surgical approach for the treatment of lymphoedema.

An Innovative and Economical Device for Ischemic Preconditioning of the Forehead Flap Prior to Pedicle Division: A Comparative Study.

BACKGROUND: Ischemic preconditioning of the forehead flap prior to pedicle division helps to improve angiogenesis. Clamping the pedicle by a clamped rubber band with vessel forceps is often clinically applied. However, the severe pain and unstable blocking effect influenced the preconditioning process. In this study, we described an innovative device designed for ischemic preconditioning and compared its efficacy with the clamped rubber band. METHODS: The device consists of a self-locking nylon cable tie with a buckle and a rubber tube. The rubber tube is fed over the cable tie to act as a soft outer lining and the cable tie is tightened across the pedicle to block the perfusion for ischemic preconditioning. This device and the standard clamped rubber band were applied respectively before division surgery. The constriction effect, reliability, reproducibility, and the patients' pain tolerance were compared. RESULTS: A total of 20 forehead flaps were included. The cable tie had less incidence of loosening (7.7% vs. 16.6%, p < 0.05) and maintained the pressure more effectively. The pain score for the nylon cable tie was significantly lower than the clamped rubber band (4.25 ± 1.02 vs. 6.75 ± 1.12, p < 0.05), especially for 10 pediatric patients (4.50 ± 0.85 vs. 8.10 ± 1.20, p < 0.01). All 20 pedicles were successfully divided at 19 to 22 days with no surgical complications. CONCLUSION: Compared with the clamped rubber band, the cable tie produces a more reliable and reproducible ischemic preconditioning effect. It is also better tolerated by the patients. Therefore, we recommend using the nylon cable tie as the preferred device for ischemic preconditioning of the forehead flap.

Septal Reconstruction With Folded Porous Polythylene Implants: An Alternative Technique for the Correction of Severe Saddle Nose Deformities in Asian Populations.

BACKGROUND: Congenital or secondary deficiency in septal cartilage leads to an unpleasant cosmetic appearance and compromised function as well. Rhinoplasty maneuvers such as spreader graft and septal extension graft with autologous tissue have been exhibited to correct the deformities. However, the relatively severe donor site morbidity stands as a main concern for both surgeons and patients. METHODS: From January of 2014 to April of 2018, 52 patients presenting septal deformities underwent rhinoplasty with our modified technique. A piece of Medpor (8438) was tailored, folded and then placed as a combination of spreader and septal extension graft. The surgical outcomes were evaluated both objectively and subjectively. RESULTS: All the patients were followed up for 12 to 24 months postoperatively. The ratio of tip projection and the nasal length exhibited significant improvement in all our patients. Nasal obstruction subjectively mended among the 24 patients who had airway obstruction complaint preoperatively. Only 2 patients had severe adverse events and the implants were removed instantly. CONCLUSIONS: With our modified technique, Medpor proved to be an effective and reliable material for the reconstruction of septal cartilage, which provides us an alternative way to achieve extended spreader and septal extension graft with one single implant in the correction of saddle nose.Level of Evidence: Level IV, therapeutic study.

Treatment of Gastrocnemius Muscle Hypertrophy with Botulinum Toxin Injection Followed by Magnetic Resonance Imaging Assessment and 3-Dimensional Evaluation.

BACKGROUND: Hypertrophy of the gastrocnemius muscle is considered to be a hindrance to lower leg beauty in the Asian aesthetic market. A noninvasive technique that has been gaining recognition involves botulinum toxin A injection; however, there are no proper guidelines or standardized protocols for the administration of botulinum toxin to correct gastrocnemius hypertrophy. OBJECTIVES: This study sought to determine the most effective botulinum toxin injection method for correcting the contour of the lower leg calf, as well as to determine the dose that can produce the maximum effect in meeting the demands of the physician and patient. METHODS: Eighteen female patients aged between 18 and 35 years were enrolled in this study from January 2015 to July 2015. Two injection methods were compared: (I) 48 injection points with a distance of 2 cm between every point; and (II) 10 injection points. Magnetic resonance imaging examinations were conducted at baseline prior to treatment and at one month and 6 months after treatment. A 3-dimensional study was performed to analyze the volumetric changes. RESULTS: The most effective and significant treatment method for hypertrophic gastrocnemius muscle was the 48-point method (scattering injection). Following injection, this method exhibited a significant level of satisfaction with outcome. CONCLUSIONS: Our study reveals that injection dosage and method have a strong relationship with achieving a better contouring result. LEVEL OF EVIDENCE: 3.

Alteration of Skin Mechanical Properties in Patients Undergoing Botulinum Toxin Type A Injections of Forehead Rhytides.

BACKGROUND: Although application of botulinum toxin type A (BTX-A) for the treatment of forehead rhytides has become very popular, the effects of its intramuscular injections on the skin mechanical properties remain unclear. OBJECTIVES: We prospectively investigated the alterations in the mechanical properties of the skin of patients who received intramuscular injections of botulinum toxin A (BTX-A) for forehead rhytides and compared two injection doses. METHODS: Of the 42 enrolled patients, one randomly assigned half received intramuscular injections of two units (group I), and the other half received four units (group II) of BTX-A in each injection point. The baseline and post-treatment skin mechanical parameters, including gross elasticity (R2), net elasticity (R5), viscoelastic ratio (R6) and biological elasticity (R7), were measured using the Cutometer(®) and compared. RESULTS: Treatment with BTX-A resulted in significant overall alterations in the mechanical properties of skin at the injection sites of both treatment groups during the 16-week period, and no significant differences were observed between groups. Significant decreases in biological elasticity, net elasticity and viscoelasticity properties were observed at 2 weeks follow-up and began to recover at that time. All of the skin mechanical properties recovered to baseline levels by 16 weeks of follow-up in both dosage groups, which indicates that the higher dosage (4 units) did not delay relapse compared to the two-unit dosage. CONCLUSIONS: We concluded that intramuscular injections of BTX-A significantly regulated the gross elasticity, net elasticity, functional elasticity and viscoelastic elasticity at the injection point over a radius of 1.5 cm at 2, 4 and 8 weeks follow-up. The alteration in the skin measurements had completely diminished by the 16-week follow-up. 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 .

Preliminary Exploration: When Angiosome Meets Prefabricated Flaps.

Background The best known limitation to the use of prefabricated flaps is their limited survival area. One explanation for this is insufficient neovascularization. However, blood flow of prefabricated flaps is through their innate vascular network. This could lead one to conclude that angiosomes may impede blood perfusion. This study aims to settle this contradiction between theory and clinical practice. Methods We performed a two-stage operation of a prefabricated abdominal flap in a rat model. The rats were divided into five groups (n = 6/group). Group A: fixed pedicle at a horizontal angle; Group B: fixed pedicle at an oblique angle; Group C: fixed pedicle at a vertical angle; Group D: fixed pedicle in the same position as Group A; and Group E: axial flap. Groups A and B were prefabricated for 2 weeks and Groups C and D were prefabricated for 3 weeks. Macroscopic appearance was noted, and analysis of near-infrared fluorescence imaging and capillary density was performed. Results There was no significant difference in the flaps' survival area between Groups A and B. Group D had a significantly larger survival area when compared with Group C. The boundary between two angiosomes (medioventral line) seemed to limit the indocyanine green perfusion in Groups B, C, and E, while in Groups A and D, no such limitation was seen. Capillary density was positively correlated with neovascularization time. Conclusions Angiosomes impede blood perfusion in prefabricated flaps. Cross-bound neovascular vessels nourish the flap, thus overcoming the limitation of choke vessels.

Bipedicled Preexpanded Forehead Flaps for Simultaneous Reconstruction of Total Nasal and Upper Lip Subunits: A Novel Approach to Complex Facial Resurfacing.

Background Reconstruction of the central facial subunits is a complex and challenging task. In cases in which both the nasal and upper lip subunits are involved, a technique that can reconstruct both aesthetic units with tissue of similar color and texture from a single donor site will be ideal. In this article we present our experience with the bipedicled preexpanded forehead flap for simultaneous nasal and upper lip resurfacing. Patients and Methods Between January 2012 and January 2015 we used this technique in the simultaneous reconstruction of total nasal and upper lip subunits in five patients. All cases were for burns scar resurfacing. Results Good aesthetic results were achieved in each of our five cases to date and no complications were encountered. All donor sites closed primarily with aesthetically pleasing well-concealed linear scars. In all cases small modifications such as philtral shaping and further flap thinning were performed under local anesthesia between 6 and 12 months postoperatively Conclusion The preexpanded forehead flap provides an unparalleled color and texture match when it comes to facial resurfacing. When both total nasal and upper lip resurfacings are required, it is possible to achieve this in a single sitting from a single donor site by using a bipedicled preexpanded forehead flap.

Preliminary Outcomes of Distal IMAP and SEAP Flaps for the Treatment of Unstable Keloids Subject to Recurrent Inflammation and Infections in the Lower Sternal and Upper Abdominal Areas.

BACKGROUND: We present the clinical application of the sixth internal mammary artery perforator (IMAP) and superior epigastric artery perforator (SEAP) flaps for the treatment of defects resulting from the excision of large lower sternal and upper abdominal keloids. Perforator selection and flap design were based solely on preoperative multidetector-row computed tomographic angiography (MDCTA) of the areas adjacent to the soft tissue defects. METHODS: Between January 2009 and June 2014, 15 patients with large, unstable keloids subject to recurrent inflammation and infections and with a history of multiple failed treatments underwent surgical excision and early postoperative radiation therapy. The defects were located in the upper abdomen (n = 6) or lower sternum (n = 9). All patients underwent preoperative MDCTA for perforator localization. RESULTS: A total of 15 patients underwent keloid removal followed by IMAP (n = 10) and SEAP (n = 6) flap coverage combined with early postoperative low-dose radiation therapy (350 cGy/5 fractions/5 days or 400 cGy/4 fractions/4 days). Flap sizes ranged from 9 × 5 to 17 × 6 cm. Only one IMAP flap developed a 2 × 2 cm tip necrosis, which was managed with dressing changes. The remaining flaps healed uneventfully with no keloid recurrence at 23.4 months. In all cases, the perforator location determined by preoperative MDCTA was precisely consistent with the intraoperative findings. CONCLUSION: The sixth IMAP and SEAP flaps combined with early postoperative radiation therapy provided a valid and feasible approach for the surgical treatment of large keloids in the lower sternal and upper abdominal. MDCTA enabled detailed preoperative assessment of the perforators, facilitating both flap design and dissection, and saving operating time. Although longer follow-up is required, these preliminary results are encouraging.

Sebum Production Alteration after Botulinum Toxin Type A Injections for the Treatment of Forehead Rhytides: A Prospective Randomized Double-Blind Dose-Comparative Clinical Investigation.

BACKGROUND: Research has investigated the decrease in human skin sebum after the application of botulinum toxin. Few studies of the mechanism and objective assessments of this phenomenon have been conducted and the correlation between the sebum production and injection dosages or techniques remains unclear. OBJECTIVES: We prospectively investigated the sebum regulation and its gradient around the injection site in patients who received intramuscular injections of botulinum toxin A (BTX-A) for forehead rhytides, comparing two injection doses. METHODS: Forty-two female volunteers with rhytides on the forehead region were randomly assigned to receive 10 or 20 units of BTX-A, which was administered in five standard injection sites. The baseline and post-treatment sebum production was measured using a Sebumeter. RESULTS: Treatment with BTX-A exhibited significant sebum alteration at the injection site of both groups, with a sebum gradient surrounding the injection point. The efficacy did not improve at higher injection doses, with the four-unit regimen generally not being more potent than the two-unit regimen. The sebum production recovered to normal levels at the 16 week follow-up for both treatment groups, indicating that a higher dosage (four units) did not result in a longer duration until relapse compared with the two-unit dose. CONCLUSIONS: We determined that the sebum production has a positive correlation with the distance away from the injection point. Intramuscular injection of BTX-A significantly reduces sebum production at the injection site but increases the sebum production of the surrounding skin at a radius of 2.5 cm at the 2, 4, and 8 week follow-ups. LEVEL OF EVIDENCE: 2 Therapeutic.

Objective breast volume, shape and surface area assessment: a systematic review of breast measurement methods.

BACKGROUND: There are many methods of measuring the breast and their clinical applications are well described in the literature. However, there has been no attempt to compare these various methods to allow the user to have a broad overview of the subject. The authors have attempted to summarise all the available methods to measure the breast in this article to provide a useful reference for all. METHODS: A comprehensive literature search of PubMed was performed, and the resulting articles were screened and reviewed. The data regarding the methods' mechanism, reliability, time and cost were evaluated and compared. RESULTS: A total of 74 articles dating from 1970 to 2013 were included in this study. All of the methods can be classified into those that measure (1) volume, (2) shape and (3) surface area. Each category consists of several methods that work through different mechanisms and they vary in their reliability and feasibility. Based on their mechanism, the volume measurement methods were further grouped into the natural shape methods, the stereological method, the geometrical methods and the mathematical modelling method. CONCLUSIONS: More objective breast evaluation can be achieved if all three dimensions (volume, shape and surface area) are considered. In the volume measurements, 3D modelling and the MRI are the most reliable tools. Linear measurement (geometry) and mathematical modelling are less accurate but are more economical. In the shape measurements, besides the traditional linear measurement, 3D methods that can deliver colour-coded maps and Swanson's 2D photographic measurement system are capable of depicting and tracking breast shape changes after surgery. Although the surface area metric has not been used extensively, it has potential in clinical and research applications. 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.

Mini-Shaped Kiss Flap Design for Palmar and Digital Soft-Tissue Resurfacing.

BACKGROUND: Although palmar and digital soft-tissue resurfacing with intrinsic flaps may provide functional and aesthetic reconstruction, the donor site may result in a tight closure or need for a skin graft once the flap is raised. In this series, the "mini-shaped kiss flap" was used to increase the resurfacing efficiency and preserve hand function. METHODS: The mini-shaped kiss flaps, based on common palmar digital arteries (eg, princeps pollicis artery and ulnar palmar digital artery), were developed for the resurfacing of distal or proximal finger areas. The tiny skin paddles were "kissed" together and transferred as pedicled in proposed dimensions and shape. The flap size, donor/recipient site, perforator source, whether free or pedicled, surgical outcome, and donor-site morbidity were evaluated. RESULTS: Twenty mini-shaped kiss flaps were harvested for the purpose of palmar and digital resurfacing. The flap sizes varied from 3 × 1.2 cm to 5 × 2 cm. All 19 patients, aged 6 to 52 years (mean, 35 years), achieved successful reconstruction without major complications after 6- to 12-month follow-up. CONCLUSIONS: The mini-shaped kiss flap technique exhibited favorable surgical outcomes with excellent color and texture match to the recipient sites. The reverse midpalm, thenar, and hypothenar island flap can be raised at the cost of an unnoticeable linear scar with minimized functional compromise in the donor area. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Synchronous supraclavicular vascularized lymph node transfer and liposuction for gynecological cancer-related lower extremity lymphedema: A clinical comparative analysis of three different procedures.

OBJECTIVE: Gynecological cancer-related lower extremity lymphedema (GC-LEL), a chronic, progressive condition, lacks a standardized treatment. Currently, supraclavicular vascularized lymph node transfer (SC-VLNT) is a favored approach in the treatment of lymphedema, and there is a trend toward combination technology. This study conducts a comparative analysis of three techniques for treating GC-LEL with simultaneous SC-VLNT and liposuction. METHODS: A cohort of 35 patients with GC-LEL was examined, comprising 13 patients who underwent single lymph nodes flap with a skin paddle (SLNF+P), 12 who received single lymph nodes flap without a skin paddle (SLNF), and 10 who accepted dual lymph nodes flap without a skin paddle (DLNF). Patient demographics and outcomes were meticulously documented, covering intra- and postoperative variables. RESULTS: The median limb volume reduction were 56.4% (SLNF+P), 60.8% (SLNF), and 50.5% (DLNF) in stage II, and 54.0% (SLNF+P), 59.8% (SLNF), and 54.4% (DLNF) in stage III. DLNF group procedures entailed longer flap harvesting and transplantation times. The SLNF+P group, on average, had an 8-day postoperative hospitalization, longer than others. All patients noted subjective improvements in Lymphedema Quality of Life scores, with lymphoscintigraphy revealing enhanced lymphatic flow in 29 of the 35 cases. A notable decrease in cellulitis incidence was observed. Additionally, the occurrence of cellulitis decreased significantly, except for DLNF (Stage Ⅱ). The median follow-up time was 16 months (range, 12-36 months), with no reported severe postoperative complications. CONCLUSIONS: For advanced GC-LEL, SLNF combined with liposuction is a preferred treatment, offering fewer complications, shorter operative time, and hospitalization.

Cuproptosis-related LncRNAs are correlated with immunity and predict prognosis in HNSC independent of TMB.

Aims: Cuproptosis is a novel cell death pathway, and the regulatory mechanism in head and neck squamous cell carcinoma (HNSC) remains to be explored. We determined whether cuproptosis-related lncRNAs (CRLs) could predict prognosis in HNSC. Methods and Results: First, we identified 10 prognostic CRLs by Pearson correlation and univariate Cox regression analyses. Next, we constructed the CRLs prognostic model based on 5 CRLs screened by the least absolute shrinkage and selection operator (LASSO) Cox analysis. Following this, we calculated the risk score for HNSC patients and divided patients into high- and low-risk groups. In our prognostic model, HNSC patients with higher risk scores had poorer outcomes. Based on several prognostic features, a predictive nomogram was established. Furthermore, we investigated principal component analysis to distinguish two groups, and functional enrichment analysis of 176 differentially expressed genes (DEGs) between risk groups was performed. Finally, we analyzed relationships between tumor mutation burden (TMB) and risk scores. Conclusion: Cuproptosis-related lncRNAs can be applied to predict HNSC prognosis independent of TMB, which is closely correlated with tumor immunity.

Vascularized lymph node flaps can survive on venous blood without an arterial inflow: an experimental model describing the dynamics of venous flow using indocyanine green angiography (With video).

Background: Several surgeons have described studies of free-tissue transfers using veins instead of arteries. These innovative microsurgical techniques can offer several advantages, such as an easier dissection during flap harvesting, and represent an alternative during an accidental surgical mistake or development of new surgical procedures. The purpose of this study was to describe and explore different constructs of vascularized lymph node transfer (VLNT) only based on venous blood flow in a mouse model, evaluate their blood flow microcirculation through indocyanine green (ICG) angiography and investigate the lymphatic drainage function and the lymph nodes' structures. Methods: Five types of venous lymph node flaps (LNF) were created and investigated: Types IA, IB, IC, IIA and IIB were developed by ICG intraoperatively (with videos in the article). Seven weeks later, by applying methylene blue, the recanalization of the lymphatic vessels between the LNF and the recipient site was detected. Lymph nodes were collected at the same time and their structures were analyzed by hematoxylin and eosin staining analysis. Results: All of the venous LNFs developed except Type IC. Seven weeks later, methylene blue flowed into Types IA, IB, IIA and IIB from recipient sites. When comparing with arteriovenous lymph node, the medullary sinus was diffusely distributed in venous lymph nodes. The proportion of cells was significantly reduced (p < 0.05). The artery diameters were significantly smaller (p < 0.05). The veins diameters and lymphatic vessels output in Types IA, IB, IIA and IIB were more dilated (p < 0.05). Conclusions: This research demonstrated that Type IA, IB, IIA and IIB venous LNFs can retrogradely receive venous blood supply; they can survive, produce a lymphatic recanalization and integrate with the surrounding tissue, despite lymph node structural changes. Our results will improve the understanding of the survival mechanism of venous LNFs and will help researchers to design new studies or lymphatic models and eventually find an alternative procedure for the surgical treatment of lymphedema.

Using Zhang's supertension-relieving suture technique with slowly-absorbable barbed sutures in the management of pathological scars: a multicenter retrospective study.

Background: An ideal tension-relieving suture should be efficient for >3 months to retrieve normal tensile strength. Most preexisting suturing techniques provided tension elimination followed by relapse and scar proliferation due to absorption and cut-through of the sutures. This study introduces a simple but effective suture technique developed by a senior author (ZYX) to solve this problem. Methods: A total of 120 patients with pathological scar (PS) had intervention treatment with the proposed suturing strategy at three centers from January 2018 to January 2021. A slowly absorbable 2-0 barbed suture was used for subcutaneous tension relieving with a set-back from the wound edge and a horizontal interval between proposed inserting points of 1 cm. The Patient and Observer Scar Assessment Scale (POSAS), scar width, perfusion and eversion of the wound edge were evaluated at 3-, 6- and 12-month follow-up. The time needed to place the tension-relieving suture was recorded and relapse was monitored for 18 months postoperatively. Results: In total, 76 trunks, 32 extremities and 12 cervical PS were included, with an average subcutaneous tension-relieving suture time of 5 min. The Patient and Observer Scar Assessment Scale (POSAS) score decreased from 84.70 ± 7.06 preoperatively to 28.83 ± 3.09, 26.14 ± 1.92 and 24.71 ± 2.00 at 3, 6 and 12 months postoperatively, respectively (p < 0.0001). The scar widths were 0.17 ± 0.08, 0.25 ± 0.09 and 0.33 ± 0.10 cm, respectively, with perfusion significantly decreased from 213.64 ± 14.97 to 112.23 ± 8.18 at 6 months (p < 0.0001). The wound edge flattened out during the first 3 months in most cases with only two scar relapses. Conclusions: Zhang's suture technique provides a rapid and long-lasting tension-relieving effect with ideal scar appearances and lower relapse rates in the surgical management of PS.

Medial Plantar Artery Perforator Kiss Flap for Salvage of Extensive Palmar Skin Defect.

BACKGROUND: Flaps based on the medial plantar artery (MPA) accomplish favorable surgical outcomes in palmar resurfacing due to its outstanding texture, pliability and contour, but primary closure could not be achieved at the donor site when the flap was designed to be relatively large. In this study, the kiss technique was employed for the reconstruction of extensive palmar defects which minimized donor site morbidity. METHODS: A modified flap surgical strategy was systemically developed based on the perforator distribution of the MPA through our cadaver study. Two or three narrow small skin paddles based on MPA were raised and resembled at the recipient site as a larger flap. S-2PD, hypersensitivity and ROM, QuickDASH, gait and patient satisfaction were evaluated 6 months to 12 months postoperation. RESULTS: From June 2015 to July 2021, 20 cases of reconstruction using the medial plantar artery perforator (MPAP) kiss flap were performed for the resurfacing of palmar skin defects. All flaps survived uneventfully with coverage matching the texture and color of the recipients except one flap that exhibited venous congestion and recovered after revision. 12 flaps (60 percent) were double-paddled and 8 flaps (40%) were triple-paddled with a resurfacing area of 27.19cm 2 and 41.1cm 2 respectively. All donor sites achieved primary closure without major complications. CONCLUSIONS: Versatile kiss flap combinations were developed based on further understanding of the MPA system. Durable and pliable characters of the MPAP flap provide excellent reconstruction for extensive palmar defects while minimizing donor site complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Effects and Progress of Photo-Crosslinking Hydrogels in Wound Healing Improvement.

Wound healing is a dynamic physiological process, including three stages: inflammation, tissue formation, and remodeling. The quality of wound healing is affected by many topical and systemic factors, while any small factor may affect the process. Therefore, improving the quality of wound healing is a complex and arduous challenge. Photo-crosslinking reaction using visible light irradiation is a novel method for hydrogel preparation. Photo-crosslinking hydrogels can be controlled in time and space, and are not interfered by temperature conditions, which have been widely used in the fields of medicine and engineering. This review aims to summarize the application of photo-crosslinking hydrogels in improving the quality of wound healing, mainly including the material design, application mechanism, and effect of photo-crosslinking hydrogels applied in wound healing, followed by the applicable animal models for experimental research. Finally, this review analyzes the clinical application prospects of photo-crosslinking hydrogels in the field of wound healing.

Microneedle delivery of botulinum toxin type A combined with hyaluronic acid for the synergetic management of multiple sternal keloids with oily skin: A retrospective clinical investigation.

BACKGROUND: For the treatment of sternal keloids, corticosteroid therapy has side effects including abnormal sebum secretion and acne. Relapse of keloids is common after corticosteroid injection in patients with oily skin. To reduce side effects and keloid recurrence, we used a combination of botulinum toxin type A (BTX-A) and hyaluronic acid (HA) as synergetic management for multiple sternal keloids in patients with oily skin. METHODS: In total, 58 patients with multiple sternal keloids who received monthly steroid injections were retrospectively included. Thirty-two patients in the intervention group received an additional injection of BTX-A/HA on the same day as the first injection of the steroid, while the remaining 26 patients were treated as the control group. At baseline and follow-up visits, sebum production and transepidermal water loss (TEWL) were assessed as primary outcomes, and the Vancouver Scar Scale (VSS) score, keloid recurrence, visual analog scale (VAS) score, and patient satisfaction were assessed as secondary outcomes. RESULTS: In the control group, average sebum production and TEWL were increased to 132% and 104% of baseline, respectively, at the 24-week follow-up. In the intervention group, average sebum production and TEWL reached nadir at the 8-week follow-up and then increased to 96% and 91% of baseline, respectively, at the 24-week follow-up. Sternal keloid relapse was observed in 88.5% of the patients in the control group and none of the patients in the intervention group. The total VSS score at 24 weeks was 11.04 ± 0.14 and 8.93 ± 0.26 (p < 0.001) in the control group and intervention group, respectively, and the VAS score was 75 ± 5.10 and 19.14 ± 3.80 (p < 0.001) in the control group and intervention group, respectively. Higher patient satisfaction was reported in the intervention group. CONCLUSIONS: Microneedle delivery of BTX-A/HA decreases sebum production while improving skin barrier function. Thus, this combined therapy can relieve the side effects of corticosteroid therapy and reduce keloid recurrence.