Rabbit Ear Research Articles

NIR-II light based combinatorial management of hypertrophic scar by inducing autophagy in fibroblasts

The hypertrophic scar (HS) is a prevalent cutaneous fibrotic disorder that impacts both the aesthetic and functional aspects of the skin, there is an urgent need for a highly safe and effective approach to address the challenge of HS with thick and deep types. Inspired by the superior deep tissue penetrative ability of near-infrared-II (NIR-II) light and potential mitochondria ROS inducing effect of Chinese medicine lycorine (LYC), we fabricated a Cu2Se@LYC (CL) composite by encapsulating LYC on polyvinyl pyrrolidone (PVP) modified Cu2Se nanoparticles. After NIR-II irradiation, CL could induce the generation of reactive oxygen species (ROS) and mitochondrial damage in hypertrophic scar fibroblasts (HSFs). The subsequent release of cytochrome C (cyt-c) from mitochondria into the cytoplasm and upregulation of beclin1 leads to the activation of endogenous apoptosis and autophagy-mediated cell death. The CL + NIR-II treatment exhibited a pronounced anti-scarring effect in both in vitro and in vivo rabbit ear scar models, leading to a significant reduction in the fibrotic markers including Collagen I/III and α-smooth muscle actin (α-SMA). This study comprehensively investigated the crucial role of HSFs’ autophagy in scar management and proposed a safe and effective therapy based on NIR-II laser for clinical application.

A New Strategy to Inhibit Scar Formation by Accelerating Normal Healing Using Silicate Bioactive Materials.

Inspired by the scar-free wound healing in infants, an anti-scar strategy is proposed by accelerating wound healing using silicate bioactive materials. Bioglass/alginate composite hydrogels are applied, which significantly inhibit scar formation in rabbit ear scar models. The underlining mechanisms include stimulation of Integrin Subunit Alpha 2 expression in dermal fibroblasts to accelerate wound healing, and induction of apoptosis of hypertrophic scar fibroblasts by directly stimulating the N-Acylsphingosine Amidohydrolase 2 expression in hypertrophic scar fibroblasts, and indirectly upregulating the secretion of Cathepsin K in dermal fibroblasts. Considering specific functions of the bioactive silicate materials, two scar treatment regimes are tested. For severe scars, a regenerative intervention is applied by surgical removal of the scar followed by the treatment with bioactive hydrogels to reduce the formation of scars by activating dermal fibroblasts. For mild scars, the bioactive dressing is applied on the formed scar and reduces scar by inducing scar fibroblasts apoptosis.

Mantle melting in regions of thick continental lithosphere: Examples from Late Cretaceous and younger volcanic rocks, Southern Rocky Mountains, Colorado (USA)

Major- and trace-element data together with Nd and Sr isotopic compositions and 40Ar/39Ar age determinations were obtained for Late Cretaceous and younger volcanic rocks from north-central Colorado, USA, in the Southern Rocky Mountains to assess the sources of mantle-derived melts in a region underlain by thick (≥150 km) continental lithosphere. Trachybasalt to trachyandesite lava flows and volcanic cobbles of the Upper Cretaceous Windy Gap Volcanic Member of the Middle Park Formation have low εNd(t) values from −3.4 to −13, 87Sr/86Sr(t) from ~0.705 to ~0.707, high large ion lithophile element/high field strength element ratios, and low Ta/Th (≤0.2) values. These characteristics are consistent with the production of mafic melts during the Late Cretaceous to early Cenozoic Laramide orogeny through flux melting of asthenosphere above shallowly subducting and dehydrating oceanic lithosphere of the Farallon plate, followed by the interaction of these melts with preexisting, low εNd(t), continental lithospheric mantle during ascent. This scenario requires that asthenospheric melting occurred beneath continental lithosphere as thick as 200 km, in accordance with mantle xenoliths entrained in localized Devonian-age kimberlites. Such depths are consistent with the abundances of heavy rare earth elements (Yb, Sc) in the Laramide volcanic rocks, which require parental melts derived from garnet-bearing mantle source rocks. New 40Ar/39Ar ages from the Rabbit Ears and Elkhead Mountains volcanic fields confirm that mafic magmatism was reestablished in this region ca. 28 Ma after a hiatus of over 30 m.y. and that the locus of volcanism migrated to the west through time. These rocks have εNd(t) and 87Sr/86Sr(t) values equivalent to their older counterparts (−3.5 to −13 and 0.7038–0.7060, respectively), but they have higher average chondrite-normalized La/Yb values (~22 vs. ~10), and, for the Rabbit Ears volcanic field, higher and more variable Ta/Th values (0.29–0.43). The latter are general characteristics of all other post– 40 Ma volcanic rocks in north-central Colorado for which literature data are available. Transitions from low to intermediate Ta/Th mafic volcanism occurred diachronously across southwest North America and are interpreted to have been a consequence of melting of continental lithospheric mantle previously metasomatized by aqueous fluids derived from the underthrusted Farallon plate. Melting occurred as remnants of the Farallon plate were removed and the continental lithospheric mantle was conductively heated by upwelling asthenosphere. A similar model can be applied to post–40 Ma magmatism in north-central Colorado, with periodic, east to west, removal of stranded remnants of the Farallon plate from the base of the continental lithospheric mantle accounting for the production, and western migration, of volcanism. The estimated depth of the lithosphere-asthenosphere boundary in north-central Colorado (~150 km) indicates that the lithosphere remains too thick to allow widespread melting of upwelling asthenosphere even after lithospheric thinning in the Cenozoic. The preservation of thick continental lithospheric mantle may account for the absence of oceanic-island basalt–like basaltic volcanism (high Ta/Th values of ~1 and εNd[t] > 0), in contrast to areas of southwest North America that experienced larger-magnitude extension and lithosphere thinning, where oceanic-island basalt–like late Cenozoic basalts are common.

The effectiveness of antimicrobial photodynamic therapy on catheter infection model

Background/AimThis experimental study aimed to examine the effectiveness of transdermal antimicrobial photodynamic therapy (APDT) with and without antimicrobial lock therapy (ALT), on catheter biofilms. MethodsS. epidermidis and C. orthopsilosis biofilms were formed within peripheral venous catheters positioned in the marginal ear veins of New Zealand white rabbits. Biofilm formation was confirmed with scanning electron microscopy in two catheters. 24 catheters with staphylococcal biofilms and 24 with fungal biofilms were treated with APDT, ALT or “APDT plus ALT” for five days. Six catheters were separated as controls. APDT was applied with a red colored LED lamp and methylene blue as the photosensitizer. Vancomycin lock solutions were used as ALT for staphylococcal biofilms and amphotericin B for fungal biofilms. The effect of treatment procedures was evaluated by intraluminal biofilm viability testing based on spectrophotometric evaluation, and a quantitative (OD) value was obtained for each catheter. ResultsThe mean OD values obtained by 600 nm spectrophotometric reading at 24 h (biofilm viability) after “ALT”, “APDT” and “ALT plus APDT” procedures were 0.363, 0.151 and 0.128 for S. epidermidis and 0.092, 0.104 and 0.227 for C. orthopsilosis, respectively. All these OD values obtained after treatment procedures were lower than controls for both S. epidermidis (OD: 0,802) and C. orthopsilosis (OD: 0,315), although there were large fluctuations in our results. ConclusionsOur results suggest that transdermal APDT may be an effective method for treating staphylococcal and candida biofilms formed within intravenous catheters in our rabbit ear model. The combined use of APDT and ALT might be beneficial in these staphylococcal biofilms.

Fusible and Radiopaque Microspheres for Embolization.

In this work, fusible microspheres loaded with radiopaque agents as an embolic agent for transcatheter arterial embolization (TAE) are developed. A poly(ethylene glycol) (PEG) and poly(ε-caprolactone) (PCL) multi-block copolymer basing polyurethane (PCEU) is synthesized and fabricated into blank microspheres (BMs). The microspheres are elastic in compression test. A clinical contrast agent lipiodol is encapsulated in the microspheres to receive fusible radiopaque microspheres (FRMs). The sizes of FRMs are uniform and range from 142.2 to 343.1µm. The encapsulated lipiodol acts as the plasticizer to reduce the melting temperature point (Tm) of PECU microspheres, thus, leading to the fusion of microspheres to exhibit efficient embolization in vivo. The performance of FRMs is carried out on a rabbit ear embolization model. Serious ischemic necrosis is observed and the radiopacity of FRMs sustains much longer time than that of commercial contrast agent Loversol in vivo. The fusible and radiopaque microsphere is promising to be developed as an exciting embolic agent.

Dual-Modal Optical Imaging of Tissue Perfusion in Response to Cooling Stimulation Facilitates Early Detection of Pressure Ulcer.

Pressure ulcers present a significant human and economic challenge, lacking a reliable method for early detection. To address this, we developed a system capable of early detection by using cooling stimulation and dynamic data acquisition techniques to monitor blood perfusion and skin temperature. The system consists of laser speckle perfusion imaging and thermal imaging. And we performed simulations to demonstrate that the system is capable of detect tissue damage across multiple layers, from superficial to deep. Testing on a rabbit ear model demonstrated that this approach, which combines dynamic perfusion and temperature parameters, effectively distinguishes early pressure ulcer areas from normal skin with a significant p value of 0.0015. This distinction was more precise compared to methods relying solely on static parameters or one parameter. Our study thereby offers a promising advancement in the proactive management and prevention of pressure ulcers.

Real-time mapping of photo-sono therapy induced cavitation using Doppler optical coherence tomography.

Photo-sono therapy (PST) is an innovative anti-vascular approach based on cavitation-induced spallation. Currently, passive cavitation detection (PCD) is the prevalent technique for cavitation monitoring during treatment. However, the limitations of PCD are the lack of spatial information of bubbles and the difficulty of integration with the PST system. To address this, we proposed a new, to the best of our knowledge, cavitation mapping method that integrates Doppler optical coherence tomography (OCT) with PST to visualize bubble dynamics in real time. The feasibility of the proposed system has been confirmed through experiments on vascular-mimicking phantoms and in vivo rabbit ear vessels, and the results are compared to high-speed camera observations and PCD data. The findings demonstrate that Doppler OCT effectively maps cavitation in real time and holds promise for guiding PST treatments and other cavitation-related clinical applications.

The topical application of Sphistin12-38 in combination with sponge spicules for the acne treatment.

We demonstrated for the first time that a marine-derived antimicrobial peptide (AMP), Sph12-38, exhibit high antimicrobial activity against P. acnes with a minimum bactericidal concentration (MBC) value of 7μM. Meanwhile, Sph12-38 has no significant cytotoxicity to human keratinocytes (HKs) at its high concentration (33.5μM). The topical application of sponge Haliclona sp. spicules (SHS) dramatically enhanced the skin penetration of Sph12-38 up to 40.9 ± 5.9% (p < 0.01), which was 6.1 ± 0.9-fold higher than that of Sph12-38 alone. Further, SHS resulted in the accumulation of most Sph12-38 in viable epidermis and dermis. Further, the combined use of Sph12-38 and SHS resulted in a cure rate of 100% for rabbit ear acne treatment in vivo for two weeks, while the one induced by other groups was 40%, 0% and 0% for SHS alone, Sph12-38 alone and control group, respectively. The strategy of combined using AMP and SHS can also be applied in a rational designed topical delivery system for the management of other deep infection of the skin. The effectiveness of SHS by itself on the treatment of acne was also demonstrated by clinical trials. After 14days of treatment by 1% SHS gel. The number of skin lesions decreased by 51.4%.

Microspheres-mediated magnetic thermal ablation combined with immune checkpoint blockade therapy for liver cancer

Hepatocellular carcinoma (HCC) are some of the most difficult malignant tumors to treat, due to their high rates of metastasis and recurrence. Image-guided percutaneous ablation, which serves as an important means in HCC treatment. However, drawbacks such as puncture injury, metastasis, and a limited ablation range still exist. Therefore, A highly effective and non-invasive magnetic thermal ablation (MTA) scheme for HCC was proposed by precisely embolizing magnetic microspheres into tumor-feeding arteries. In this study, polyacrylamide (PAM) and ferric oxide (Fe3O4) were utilized to prepare uniformly sized PAM@Fe3O4 microspheres with excellent eddy current heating effects. Additionally, a combined approach of MTA and immunotherapy was suggested. MTA combined with immune checkpoint blockade therapy efficiently ablated primary tumors and inhibited simulated metastatic tumors in mice. Further arterial embolization experiments in rabbit ears and renal arteries demonstrated the effective retention of PAM@Fe3O4 microspheres in blood vessels for MTA. Finally, we successfully applied PAM@Fe3O4 microspheres for efficient MTA therapy in a rabbit VX2 in situ liver tumor model. The aim of research is to provide new strategies for clinical HCC treatment, promoting the transition from image-guided percutaneous minimally invasive ablation to noninvasive ablation. This significant transition holds the potential for clinical applicability.

Auricular cartilage regeneration using chondroitin sulfate-based hydrogel with mesenchymal stem cells in rabbits.

Cartilage is an avascular and alymphatic tissue that lacks the intrinsic ability to undergo spontaneous repair and regeneration in the event of significant injury. The efficacy of conventional therapies for invasive cartilage injuries is limited, thereby prompting the emergence of cartilage tissue engineering as a possible alternative. In this study, we fabricated three-dimensional hydrogel films utilizing sodium alginate (SA), gelatin (Gel), and chondroitin sulfate (CS). These films were included with Wharton's jelly mesenchymal stem cells (WJ-MSCs) and intended for cartilage tissue regeneration. The hydrogel film that were prepared underwent evaluation using various techniques including scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, assessment of the degree of swelling, degradation analysis, determination of water vapor transmission rate (WVTR), measurement of water contact angle (WCA), evaluation of mechanical strength, and assessment of biocompatibility. The rabbit ear cartilage regeneration by hydrogel films with and without of WJ-MSCs was studied by histopathological investigations during 15, 30, and 60 days. The hydrogel films containing CS exhibited superior metrics compared to other nanocomposites such as better mechanical strength (12.87 MPa in SA/Gel compared to 15.56 in SA/Gel/CS), stability, hydrophilicity, WVTR (3103.33 g/m2/day in SA/Gel compared to 2646.67 in nanocomposites containing CS), and swelling ratio (6.97 to 12.11% in SA/Gel composite compared to 5.03 to 10.90% in SA/Gel/CS). Histopathological studies showed the presence of chondrocyte cells in the lacunae on the 30th day and the complete restoration of the cartilage tissue on the 60th day following the injury in the group of SA/Gel/CS hydrogel containing WJ-MSCs. We successfully fabricated a scaffold composed of alginate, gelatin, and chondroitin sulfate. This scaffold was further enhanced by the incorporation of Wharton's jelly mesenchymal stem cells. Our findings demonstrate that this composite scaffold has remarkable biocompatibility and mechanical characteristics. The present study successfully demonstrated the therapeutic potential of the SA-Gel-CS hydrogel containing WJ-MSCs for cartilage regeneration in rabbits.

ECM derivatized alginate augmenting bio-functionalities of lyophilized mat for skin and liver wound treatment

Peptides and molecular residues sourced from the fragmentation of the extracellular matrix (ECM) can exacerbate a plethora of cellular functions. We selected a natural ECM-derived complex peptide mixture to functionalize sodium alginate. Three alginate derivatives (sodium alginate conjugated with ECM) SALE-1, SALE-2, and SALE-3 were synthesized using the lowest (10 % w/w), moderate (50 % w/w), and highest (100 % w/w) concentrations of ECM. Thereafter, they were used to fabricate three groups of mat scaffolds EMAT-1 (ECM derivatized alginate thrombin-mat), EMAT-2, and EMAT-3, respectively by the freeze-drying process. To enhance the hemostatic activity, thrombin was loaded onto the scaffolds. Another group, AT, without any derivatized alginate was additionally included in order to comparative analysis. Physical characteristics revealed that the porous mat scaffold showed enhancement in degradation and swelling ability with the increase in ECM content. The higher cell proliferation, migration, and cell viability were noticed in the higher ECM-containing samples EMAT-2 and EMAT-3. In vivo studies using rodent hepatic and rabbit ear models were carried out to ensure the hemostatic ability of the scaffolds. EMAT-2 and EMAT-3 demonstrate excellent liver regeneration ability in rat models. Moreover, the rat cutaneous wound model depicted that EMAT-3 dramatically elevated the skin's healing ability, thereby rendering it an excellent candidate for future clinical application in wound healing.

Biodegradable Microembolics with Nanografted Polyanions Enable High-Efficiency Drug Loading and Sustained Deep-Tumor Drug Penetration for Locoregional Chemoembolization Treatment.

Transarterial chemoembolization (TACE), the mainstay treatment of unresectable primary liver cancer that primarily employs nondegradable drug-loaded embolic agents to achieve synergistic vascular embolization and locoregional chemotherapy effects, suffers from an inferior drug burst behavior lacking long-term drug release controllability that severely limits the TACE efficacy. Here we developed gelatin-based drug-eluting microembolics grafted with nanosized poly(acrylic acid) serving as a biodegradable ion-exchange platform that leverages a counterion condensation effect to achieve high-efficiency electrostatic drug loading with electropositive drugs such as doxorubicin (i.e., drug loading capacity >34 mg/mL, encapsulation efficiency >98%, and loading time <10 min) and an enzymatic surface-erosion degradation pattern (∼2 months) to offer sustained locoregional pharmacokinetics with long-lasting deep-tumor retention capability for TACE treatment. The microembolics demonstrated facile microcatheter deliverability in a healthy porcine liver embolization model, superior tumor-killing capacity in a rabbit VX2 liver cancer embolization model, and stabilized extravascular drug penetration depth (>3 mm for 3 months) in a rabbit ear embolization model. Importantly, the microembolics finally exhibited vessel remodeling-induced permanent embolization with minimal inflammation responses after complete degradation. Such a biodegradable ion-exchange drug carrier provides an effective and versatile strategy for enhancing long-term therapeutic responses of various local chemotherapy treatments.

Isorhamnetin inhibits hypertrophic scar formation through TGF-β1/Smad and TGF-β1/CREB3L1 signaling pathways

BackgroundHypertrophic scar (HS) is a common fibrotic skin disease that occurs secondary to burns or injuries. The activation of the TGF-β signaling pathway contributes immensely to HS formation. Isorhamnetin (ISO) is a type of flavonoid compound that exerts an antifibrotic effect via TGF-β signaling suppression. However, whether ISO can inhibit HS formation via TGF-β signaling is yet to be elucidated. This study aimed to examine the influence of ISO on HS pathogenesis and TGF-β signaling, especially the downstream molecules and networks of TGF-β signaling that facilitate HS formation. MethodsHypertrophic scar fibroblasts (HSFBs) were isolated from human HS tissues. The in vitro proliferation, migration, contractile ability, cell cycle, and apoptosis of HSFBs after ISO treatment were determined using cell viability assay, EdU staining, wound healing assay, collagen gel contraction assay, and flow cytometry. The expressions of genes and proteins involved in TGF-β signaling and its downstream molecules in ISO-treated HSFBs were determined using quantitative PCR (qPCR), immunofluorescence, and western blotting. In vivo, a rabbit HS model was established, and the effects of ISO on rabbit HS formation were investigated using histological analysis, immunohistochemical staining, and qPCR. ResultsIn vitro studies indicated that ISO treatment suppressed the proliferation, migration, and contractile ability of HSFBs; attenuated the expressions of COL Ⅰ, COL Ⅲ, and α-SMA; and inhibited TGF-β1 signaling-induced activation of HSFBs by decreasing the levels of phosphorylated Smad2/3 and cleaved CREB3L1 in a dose-dependent manner. Furthermore, ISO augmented apoptosis and G2 phase cell cycle arrest of HSFBs by upregulating the expressions of the proapoptotic proteins Bax and cleaved caspase-3 and downregulating the expression of the antiapoptotic protein Bcl-2. In vivo studies revealed that ISO ameliorated HS formation in the rabbit ear by lowering the scar elevation index, attenuating the collagen density, facilitating the regular arrangement of collagen fibers, and downregulating the expressions of TGF-β1, CREB3L1, COL Ⅰ, COL Ⅲ, and α-SMA. ConclusionsISO suppressed HS pathogenesis by dampening TGF-β1/Smad and TGF-β1/CREB3L1 signaling pathways, which suggests that it may serve as a candidate inhibitor of TGF-β1 signaling and a promising anti-HS drug with a high therapeutic potential.

Effect of Averrhoa carambola L. on the Skin in an Animal Model of Hypertrophic Scarring

Introduction: Hypertrophic scarring in the skin represents a serious global public health problem, as it physically and emotionally affects people who suffer from it. This makes it necessary to investigate new alternatives for its prevention and treatment. The objective of the study was to compare the effect of Averrhoa Carambola L. (star fruit) on the skin under an animal model of hypertrophic healing. Methods: Experimental study; 10 male New Zealand breed rabbits were used, between 3 and 4 months old, with an average weight of 3 to 3.5Kg. The formation of hypertrophic scars in the ears of rabbits was induced under the model described by Morris et al. One of the groups received 1 mL of a 10% aqueous solution of the lyophilized star fruit, while the other received 1 mL of triamcinolone acetonide; in both groups the application was intralesional and weekly in a month. After the treatment, under sedation, only the hypertrophic scars were extracted using a biopsy punch and the tissues were preserved in 10% formalin for subsequent pathological examination. Results: The group that received star fruit solution significantly improved the dermis and epidermis in the hypertrophic scars on the ears of rabbits that received treatment. When compared with the group that received triamcinolone acetonide, there were no statistically significant differences. Conclusion: The lyophilized aqueous extract of star fruit at 10% demonstrated a similar effect compare to triamcinolone acetonide (treatment of choice) in reducing the fibrosis of hypertrophic scars in the ears of rabbits.

Minimally invasive surgical approach to model hypertrophic scarring in the rabbit ear.

Current strategies for hypertrophic scar prevention and treatment are limited. To facilitate these efforts, a minimally invasive hypertrophic scar model was created in a rabbit ear for the first time based on previous methods used to induce ischemia. Six New Zealand white rabbits (12 ears total) were studied. First, ischemia was achieved by ligating the cranial artery, cranial vein and central artery, while preserving the caudal artery, caudal vein and central vein, respectively. The relative level of ischemia induced at time of surgery, both baseline and maximum perfusion, was assessed with a fluorescent light-assisted angiography and demonstrated lower rates of perfusion in the ischemic ears. Following vascular injury, a 2-cm full thickness linear wound was created on the ventral ear and closed with 4 - 0 Nylon sutures under high tension. For each rabbit, one ear received a combination of ischemia and wounding with suture tension (n = 6), while the other ear was non-ischemic with wounding and suture tension alone (n = 6). Four weeks post-operatively, ischemic ears developed scar hypertrophy (histological scar thickness: 1.1 ± 0.2mm versus 0.5 ± 0.1mm, p < 0.05). Herein, we describe a novel, prototypical minimally invasive rabbit ear model of hypertrophic scar formation that can allow investigation of new drugs for scar prevention.

CD248 interacts with ECM to promote hypertrophic scar formation and development

Hypertrophic scar (HS) presents a significant clinical challenge, frequently arising as a fibrotic sequela of burn injuries and trauma. Characterized by the aberrant activation and proliferation of myofibroblasts, HS lacks a targeted therapeutic approach to effectively reduce this dysregulation. This study offers novel evidence of upregulated expression of CD248 in HS tissues compared to normal skin (NS) tissues. Specifically, the expression of CD248 was predominantly localized to α-SMA+-myofibroblasts in the dermis. To explain the functional role of CD248 in dermal myofibroblast activity, we employed a targeted anti-CD248 antibody, IgG78. Both CD248 intervention and IgG78 treatment effectively suppressed the proliferative, migratory, and ECM-synthesizing activities of myofibroblasts isolated from HS dermis. In addition, IgG78 administration significantly attenuated HS formation in an in vivo rabbit ear model. The LC/MS analysis coupled with co-immunoprecipitation of HS tissues indicated a direct interaction between CD248 and the ECM components Fibronectin (FN) and Collagen I (COL I). These findings collectively suggest that CD248 may function as a pro-fibrotic factor in HS development through its interaction with ECM constituents. The utilization of an anti-CD248 antibody, such as IgG78, represents a promising novel therapeutic strategy for the treatment of HS.

Dissolvable microneedles loaded with asiaticoside nanocrystals stabilized by Panax Notoginseng saponins for hypertrophic scar treatment

Hypertrophic scars (HS) are fibroproliferative disorders caused by overgrowth of connective tissue during wound repair, for which effective treatment is lacking. Although Asiaticoside (AS) facilitates scarless wound healing, its low permeability through the skin and poor solubility in water pose major barriers to clinical application. Dissolvable microneedles (DMNs) have emerged as a potent transdermal drug delivery technique capable of penetrating the stratum corneum barrier. However, due to the lipid-soluble nature of AS, it is incompatible with water-soluble microneedle matrices. This incompatibility could result in an uneven dispersion of drugs, making the creation of DMNs loaded with AS challenging. In this study, a pharmacodynamic molecule called Panax Notoginseng Saponins (PNS), which similarly encourages scarless wound healing, was used as a stabilizer. Asiaticoside-Panax Notoginseng Saponin (AS-PNS-NCs) were prepared by solvent evaporation coupled with ultrasonication to improve the water solubility of AS. The average particle size was 158.70 ± 10.99 nm, Polydispersity index (PDI) was 0.18 ± 0.012, and Zeta potential was −15.5 ± 1.08 mV. A centrifugal filling technique was then used to create AS-PNS-NCs-DMNs. After 24 h of in vitro transdermal drug release, the cumulative transdermal release of AS-PNS-NCs-DMNs of 319.00 ± 50.01 μg and skin retention of 80.61 ± 48.46 μg were significantly higher than those of AS-PNS-NCs- Gels (134.84 ± 27.66 μg and 5.23 ± 1.86 μg, respectively). Furthermore, it was demonstrated that AS-PNS-NCs-DMNs may suppress human skin fibroblasts (HSF) in vitro migration rate and proliferative activity. In rabbit ear keloid model, AS-PNS-NCs-DMNs (containing AS 1536.49 ± 93.14 μg/patch) reduced the collagen volume fraction (CVF) and improved the collagen fiber arrangement by inhibiting the overexpression of transforming growth factor-β1 (TGF-β1) and α-Smooth muscle actin (α-SMA) at the scar site, resulting in a reduction of scar thickness. It is demonstrated that AS-PNS-NCs-DMNs can effectively inhibit scar proliferation.

Success rate and complication prevalence of peripheral catheterization of the cephalic, lateral saphenous and marginal ear veins in pet rabbits

BackgroundIntravenous catheter placement is a routine procedure in exotic pet medicine, yet the selection of the optimal venous site for catheterization in rabbits (Oryctolagus cuniculus) remains controversial. Recommendations differ between countries and authors, and lack evidence-based data. This prospective study aimed to document and compare the prevalence and types of complications secondary to peripheral venous catheterization in domestic rabbits as related to the vein catheterized. MethodsCatheterization events (n=151) were randomly attributed to three groups, named according to the venous site selected: cephalic (n=39), lateral saphenous (n=58) and marginal ear vein (n=54). Rabbits that needed a catheter for fluid therapy, surgery, or imaging, were included in the study. Catheters were placed by three veterinarians following a standardized method. Data regarding the patient, the type of catheter, and the treatment were recorded. Complications were evaluated every day after the catheter placement, at removal and after 15 days. ResultsMinor complications that were observed included catheters which were bent at the elbow or removed by the rabbit, and twisted or chewed tubing. Ear necrosis and signs of phlebitis were considered major complications. Catheter placement failure was significantly higher in the “cephalic” group (odds ratio = 4, 95% Confidence Interval = [16.67,1.04], p = 0.048), without differences between the operators. For the marginal ear vein, there was also a significant association between the failure rate and the length of the rabbit's ear (Wilcoxon effect size = 0.42, 95% CI = [0.14,0.64], p = 0.003). No major complication was observed in any groups. Minor complications occurred without significant differences between the groups. Conclusionsand clinical relevance: The results suggest that intravenous catheters in rabbits do not carry significant complications irrespective of the chosen site, but cephalic vein placement carries the highest risk of failure.

Effect of black cloth ointment on hypertrophic scar formation: An investigation using integrated network pharmacology and animal assay.

Hypertrophic scars (HS) are a common disfiguring condition in daily clinical encounters which brings a lot of anxieties and concerns to patients, but the treatment options of HS are limited. Black cloth ointment (BCO), as a cosmetic ointment applicable to facial scars, has shown promising therapeutic effects for facial scarring. However, the molecular mechanisms underlying its therapeutic effects remain unclear. Network pharmacology was first applied to analyze the major active components of BCO and the related signaling pathways. Subsequently, rabbit ear scar model was successfully established to determine the pharmacological effects of BCO and its active component β-elemene on HS. Finally, the molecular mechanism of BCO and β-elemene was analyzed by Western blot. Through the network pharmacology, it showed that β-elemene was the main active ingredient of BCO, and it could significantly improve the pathological structure of HS and reduce collagen deposition. BCO and β-elemene could increase the expression of ER stress-related markers and promote the increase of apoptotic proteins in the Western blot experiment and induce the apoptosis of myofibroblasts. Our findings indicate that the material basis for the scar-improving effects of the BCO is β-elemene, and cellular apoptosis is the key mechanism through which the BCO and β-elemene exert their effects.

Objective Noninvasive Measurement of the Volumizing Effect of a Dermal Filler: An In Vivo Study

BackgroundInformation about the volumizing effects of dermal fillers is critical for physicians’ understanding of product features and prudent decision-making in clinical practice. It is important for material engineers to develop and optimize new dermal fillers, especially when comparing the physiochemical properties of a new product with those of existing fillers that are used worldwide.ObjectiveThis study aimed to establish a reliable, noninvasive method for in vivo quantitative evaluation of the filling effect in order to predict possible effectiveness after filler injection and to evaluate the degradation trend over time.MethodsA rabbit model of ear injection with dermal fillers was established. Hyaluronic acid (HA) filler was injected into the subcutaneous layer of rabbit ears, resulting in a stable skin bulge. Ultrasonography was used to noninvasively measure the skin bulge for volume calculation; the volume change was analyzed periodically until 38 weeks. Pathological examination, the gold standard, was performed to confirm degradation.ResultsThe immediate volumizing effect of HA filler injection was macroscopically observed as a local skin bulge. Ultrasound was able to precisely detect the shape of the filler and calculate the length, width, and height of the skin bulge at each time point. The degree of uplift and amount of residual samples in the pathological evaluation were consistent with the results of morphological observation using ultrasound.ConclusionEvaluation of the volume impact of dermal filler through the rabbit ear injection model evaluation enables material science evaluation in the early stage of material development, and has certain clinical reference value.Level of Evidence IThis 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.