Mouse Ear Research Articles

Non-invasive measurements of blood glucose levels by time-gating mid-infrared optoacoustic signals

Non-invasive glucose monitoring (NIGM) represents an attractive alternative to finger pricking for blood glucose assessment and management of diabetes. Nevertheless, current NIGM techniques do not measure glucose concentrations in blood but rely on indirect bulk measurement of glucose in interstitial fluid, where glucose is diluted and glucose dynamics are different from those in the blood, which impairs NIGM accuracy. Here we introduce a new biosensor, termed depth-gated mid-infrared optoacoustic sensor (DIROS), which allows, for the first time, non-invasive glucose detection in blood-rich volumes in the skin. DIROS minimizes interference caused by the stratum corneum and other superficial skin layers by time-gating mid-infrared optoacoustic signals to enable depth-selective localization of glucose readings in skin. In measurements on the ears of (female) mice, DIROS displays improved accuracy over bulk-tissue glucose measurements. Our work demonstrates how signal localization can improve NIGM accuracy and positions DIROS as a holistic approach, with high translational potential, that addresses a key limitation of current NIGM methods.

Anti-inflammatory effects and related mechanisms in vitro and in vivo of Hedychium coccineum rhizome essential oil

Ethnopharmacological relevanceHedychium coccineum rhizome is an anti-inflammatory ethnomedicine used to remedy inflammation-related swelling and bronchial asthma. Aim of the studyThe study aimed to analyze the phytochemical constituents of H. coccineum rhizome essential oil (EO) and evaluate its in vitro and in vivo anti-inflammatory effects and underlying mechanisms. Materials and methodsPhytochemical constituents of H. coccineum rhizome EO were analyzed using GC-FID/MS. In RAW264.7 macrophages induced by LPS, blockade of PGE2, NO, IL-1β, IL-6, and TNF-α secretion by H. coccineum rhizome EO was measured, and then Western blot, qRT-PCR, and immunofluorescent staining were used to evaluate its underlying mechanisms. Moreover, we used the xylene-induced ear edema model for testing anti-inflammatory potential in vivo and examined auricular swelling as well as tissue and serum contents of IL-1β, IL-6, and TNF-α. ResultsEO's main components were E-nerolidol (40.5%), borneol acetate (24.8%), spathulenol (4.5%), linalool (3.8%), elemol (3.5%), and borneol (3.4%). In RAW264.7 cells stimulated by LPS, EO downregulated the expression of pro-inflammatory enzyme (iNOS and COX-2) genes and proteins, thereby suppressing pro-inflammatory mediators (NO and PGE2) secretion. Simultaneously, it reduced TNF-α, IL-1β, and IL-6 release by downregulating their mRNA expression. Besides, H. coccineum EO attenuated LPS-stimulated activation of NF-κB (by reducing IκBα phosphorylation and degradation to inhibit NF-κB nuclear translocation) and MAPK (by downregulating JNK, p38, and ERK phosphorylation). In xylene-induced mouse ear edema, EO relieved auricular swelling and lowered serum and tissue levels of TNF-α, IL-1β, and IL-6. ConclusionsH. coccineum EO had powerful in vivo and in vitro anti-inflammatory effects by inhibiting MAPK and NF-κB activation. Hence, H. coccineum EO should have great potential for application in the pharmaceutical field as a novel anti-inflammatory agent.

Preparation and anti-inflammatory effect of mercury sulphide nanoparticle-loaded hydrogels

We successfully prepared mercury sulphide nanoparticle hydrogels by physical encapsulation method. The successfully prepared mercuric sulphide nanoparticle hydrogel was a zinc folate hydrogel, which showed an obvious porous structure with interconnected and uniformly distributed pores and a pore size range of about 20 μm. The maximum drug loading of the hydrogels was 3%, and the in vitro cumulative release degree was in accordance with the first-order kinetic equation Mt = 149.529 (1 − e−0.026 t ). The particles in mercuric sulphide nanoparticle hydrogels significantly down-regulated the expression of the cell surface co-stimulatory molecule CD86 (p < .0001). Meanwhile, the inflammatory response was regulated through the NF-κB pathway in LPS-induced inflammatory cells. Later, it was observed that mercuric sulphide nanoparticle hydrogels could significantly counteract the inflammatory and immune models through a mouse ear swelling model, a rat foot-plantar swelling model and a rheumatoid arthritis model. This design targets the immunomodulatory, and anti-inflammatory effects through nanocomposite hydrogel technology. It reduces the drawbacks of low mercury utilisation and susceptibility to accumulation of toxicity. It aims to provide an experimental basis for the development of mercuric sulphide and the treatment of inflammatory and immune-related diseases. Highlights Mercury sulphide nanoparticle hydrogel has an optimal mercury sulphide nanoparticle content of 2%, is structurally homogeneous and stable, and does not exhibit significant liver or kidney toxicity. Mercuric sulphide nanoparticle hydrogel exerts anti-inflammatory effects in cells and rats, and regulates the expression of macrophage surface molecules and factors related to the NF-κB pathway. Mercuric sulphide nanoparticle hydrogel improves the condition of ankle synovial joints in a rat model of rheumatoid arthritis.

Long-term, non-invasive FTIR detection of low-dose ionizing radiation exposure

Non-invasive methods of detecting radiation exposure show promise to improve upon current approaches to biological dosimetry in ease, speed, and accuracy. Here we developed a pipeline that employs Fourier transform infrared (FTIR) spectroscopy in the mid-infrared spectrum to identify a signature of low dose ionizing radiation exposure in mouse ear pinnae over time. Mice exposed to 0.1 to 2 Gy total body irradiation were repeatedly measured by FTIR at the stratum corneum of the ear pinnae. We found significant discriminative power for all doses and time-points out to 90 days after exposure. Classification accuracy was maximized when testing 14 days after exposure (specificity > 0.9 with a sensitivity threshold of 0.9) and dropped by roughly 30% sensitivity at 90 days. Infrared frequencies point towards biological changes in DNA conformation, lipid oxidation and accumulation and shifts in protein secondary structure. Since only hundreds of samples were used to learn the highly discriminative signature, developing human-relevant diagnostic capabilities is likely feasible and this non-invasive procedure points toward rapid, non-invasive, and reagent-free biodosimetry applications at population scales.

The Therapeutic Potential of Copper Peptides on Atopic Dermatitis Lesions in BALB/c mice and Human Keratinocytes

PURPOSE: Atopic dermatitis (AD), often referred to as eczema, is a chronic disease characterized by skin inflammation, itchiness, irritation, and dryness. It is caused mainly by immune dysregulation. Copper peptides (CP) have been used for a variety of skin-related purposes. In this study, we examined the effect of CP on AD induced in BALB/c mice.METHODS: BALB/c mice were separated into the following five groups: control, AD-only, AD+CP10, AD+CP100, and AD+CERA. AD was induced using house dust mite (HDM) extract and 2,4-dinitrochlorobenzene (DNCB). The mice received CP or ceramide (CERA; positive control) based on their group allocation. Histopathological analysis was performed to assess the effect of CP on mast cell infiltration. Dermal and epidermal thickness were measured using microphotographs of hematoxylin-and-eosin-stained tissue. We examined the serum immunoglobulin E (IgE) levels and mRNA gene expression of pathogenic cytokines in the mouse ear tissue and in human keratinocytes.RESULTS: CP treatment decreased dermal and epidermal mouse ear thickness and mast cell infiltration in the ear tissue in a dosedependent manner. It also decreased the serum IgE levels and the mRNA gene expression of pathogenic cytokines in the ear tissue and in the human keratinocytes. Interestingly, the therapeutic effect of CP was more robust than that of CERA.CONCLUSIONS: These results indicate that CP may have therapeutic potential against AD.

Inhibition of the ILK-AKT pathway by upregulation of PARVB contributes to the cochlear cell death in Fascin2 gene knockout mice.

The Fscn2 (Fascin2) gene encodes an actin cross-linking protein that is involved in the formation of hair cell stereocilia and retina structure. Mutations in Fscn2 gene have been linked to hearing impairment and retinal degeneration in humans and mice. To understand the function of the Fscn2 gene, we generated the Fscn2 knockout mice, which showed progressive loss of hearing and hair cells. Our goal of the present study was to investigate the mechanism underlying cochlear cell death in the Fscn2 knockout mice. Microarray analysis revealed upregulation of expression of PARVB, a local adhesion protein, in the inner ears of Fscn2 knockout mice at 8 weeks of age. Further studies showed increased levels of PARVB together with cleaved-Caspase9 and decreased levels of ILK, p-ILK, p-AKT, and Bcl-2 in the inner ears of Fscn2 knockout mice of the same age. Knockdown of Fscn2 in HEI-OCI cells led to decreased cell proliferation ability and migration rate, along with increased levels of PARVB and decreased levels of ILK, p-ILK, p-AKT, Bcl-2 and activated Rac1 and Cdc42. Overexpression of Fscn2 or inhibition of Parvb expression in HEI-OC1 cells promoted cell proliferation and migration, with increased levels of ILK, p-ILK, p-AKT, and Bcl-2. Finally, FSCN2 binds with PPAR-γ to reduce its nuclear translocation in HEI-OC1 cells, and inhibition of PPAR-γ by GW9662 decreased the level of PARVB and increased the levels of p-AKT, p-ILK, and Bcl-2. Our results suggest that FSCN2 negatively regulates PARVB expression by inhibiting the entry of PPAR-γ into the cell nucleus, resulting in inhibition of ILK-AKT related pathways and of cochlear cell survival in Fscn2 knockout mice. Our findings provide new insights and ideas for the prevention and treatment of genetic hearing loss.

NLRP3 Inflammasome Activation During Acute Negative Pressure Injury in the Middle Ear of Mice.

The present study was conducted to explore the role of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome in mouse otic barotrauma models. Previous studies suggest that the NLRP3 inflammasome plays an important role in the pathogenesis of middle ear disease. However, whether middle ear negative pressure injury underlies NLRP3 inflammasome activation remains unclear. Wild-type and Nlrp3 -/- mice were randomly assigned to control and pressure injury groups, respectively. Pressure loading was performed using a pressure cabin with the pressure level set to 20 kPa higher than that of the ambient atmosphere. This was achieved in approximately 15 seconds and maintained for 10 minutes. Hematoxylin and eosin staining was performed to detect morphological changes of the middle ear mucosa, tissue IL-1β was measured via an enzyme-linked immunosorbent assay, and cleaved caspase-1 was detected by Western blot. We found that the maturation of caspase-1 and IL-1β production in the middle ear significantly increased after otic barotrauma. In Nlrp3 -/- mice, inflammasome activation is downregulated and mucosal hyperplasia is reduced compared with those of wild-type mice during recovery. The NLRP3 inflammasome likely plays an important role in the pathogenesis of otic barotrauma. Controlling activation of the NLRP3 inflammasome may promote middle ear recovery after negative pressure injury.

Unsupervised Learning for Enhanced Computed Photoacoustic Microscopy

Photoacoustic microscopy (PAM) is a medical-imaging technique with the merits of high contrast and resolution. Nevertheless, conventional PAM scans specimens in a diameter-by-diameter fashion, resulting in a time-consuming process. Furthermore, deep-learning-based PAM image enhancement necessitates acquiring ground-truth data for training purposes. In this paper, we built an optical-resolution photoacoustic microscopy system and introduced an innovative unsupervised-learning algorithm. First, we enhanced the rotational-scanning method, transitioning from a diameter-by-diameter approach to a sector-by-sector one, significantly reducing imaging time (from 280 s to 109 s). Second, by establishing a metric for unsupervised learning, we eliminated the need for collecting reliable and high-quality ground truth, which is a challenging task in photoacoustic microscopy. A total of 324 pairs of datasets (mouse ears) were collected for unsupervised learning, with 274 for training and 50 for testing. Additionally, carbon-fiber data were sampled for lateral resolution and contrast evaluation, as well as the effective rate evaluation of the algorithm. The enhanced images demonstrated superior performance compared with that of maximum projection, both subjectively and objectively. A 76% improvement in the lateral resolution was observed. The effective rate of the algorithm was measured to be 100%, which was tested on 50 random samples. The technique presented in this paper holds substantial potential for image postprocessing and opens new avenues for unsupervised learning in photoacoustic microscopy.

Proton-FLASH: effects of ultra-high dose rate irradiation on an in-vivo mouse ear model

FLASH-radiotherapy may provide significant sparing of healthy tissue through ultra-high dose rates in protons, electrons, and x-rays while maintaining the tumor control. Key factors for the FLASH effect might be oxygen depletion, the immune system, and the irradiated blood volume, but none could be fully confirmed yet. Therefore, further investigations are necessary. We investigated the protective (tissue sparing) effect of FLASH in proton treatment using an in-vivo mouse ear model. The right ears of Balb/c mice were irradiated with 20 MeV protons at the ion microprobe SNAKE in Garching near Munich by using three dose rates (Conv = 0.06 Gy/s, Flash9 = 9.3 Gy/s and Flash930 = 930 Gy/s) at a total dose of 23 Gy or 33 Gy. The ear thickness, desquamation, and erythema combined in an inflammation score were measured for 180 days. The cytokines TGF-β1, TNF-α, IL1α, and IL1β were analyzed in the blood sampled in the first 4 weeks and at termination day. No differences in inflammation reactions were visible in the 23 Gy group for the different dose rates. In the 33 Gy group, the ear swelling and the inflammation score for Flash9 was reduced by (57 ± 12) % and (67 ± 17) % and for Flash930 by (40 ± 13) % and (50 ± 17) % compared to the Conv dose rate. No changes in the cytokines in the blood could be measured. However, an estimation of the irradiated blood volume demonstrates, that 100-times more blood is irradiated when using Conv compared to using Flash9 or Flash930. This indicates that blood might play a role in the underlying mechanisms in the protective effect of FLASH.

Resolving acne with optimized adapalene microspongeal gel, in vivo and clinical evaluations

In our pursuit of enhancing acne treatment while minimizing side effects, we developed tailored Adapalene microsponges (MS) optimized using a Box–Behnken design 33. The independent variables, Eudragit RS100 percentage in the polymer mixture, organic phase volume, and drug to polymer percentage, were explored. The optimized formulation exhibited remarkable characteristics, with a 98.3% ± 1.6 production yield, 97.3% ± 1.64 entrapment efficiency, and a particle size of 31.8 ± 1.1 µm. Notably, it achieved a 24 h cumulative drug release of 75.1% ± 1.4. To delve deeper into its efficacy, we evaluated the optimized microspongeal-gel in vitro, in vivo, and clinically. It demonstrated impressive retention in the pilosebaceous unit, a target for acne treatment. Comparative studies between our optimized Adapalene microspongeal gel and marketed Adapalene revealed superior performance. In vivo studies on Propionibacterium acnes-infected mice ears showed a remarkable 97% reduction in ear thickness, accompanied by a significant decrease in inflammatory signs and NF-κB levels, as confirmed by histopathological and histochemical examination. Moreover, in preliminary clinical evaluation, it demonstrated outstanding effectiveness in reducing comedonal lesions while causing fewer irritations. This not only indicates its potential for clinical application but also underscores its ability to enhance patient satisfaction, paving the way for future commercialization.

TPGS-mediated Transethosomes Enhance Transdermal Administration of Curcumin via Effects on Deformability and Stability.

Adding a suitable surfactant can enhance the transdermal permeability of transethosomes while also leveraging its functionality as a functional material. In this study, transethosomes were prepared using D-α-tocopherol acid polyethylene glycol succinate (TPGS) as edge activators for transdermal delivery of curcumin (Cur). The TPGS-mediated curcumin-loaded transethosomes (Cur@TES) were prepared and formulated optimally, and the optimized formulations were characterized for their morphology, particle size, entrapment efficiency (EE) and drug loading (DL). The stability and deformability of Cur@TES were investigated, while the transdermal delivery of Cur@TES was investigated through in vitro transdermal assays and fluorescence imaging. A mouse ear swelling model was performed to determine the anti-inflammatory effect of Cur@TES. Cur@TES appeared round or elliptical in shape. The particle size, EE and DL for the optimized formulation were observed as 131.2 ± 7.2 nm, 97.68 ± 2.26%, and 6.58 ± 0.62%, respectively. X-ray diffraction analysis confirmed the formation of disordered structures in the inner core of the vesicles. Moreover, Cur@TES system demonstrated better stability and deformability compared to the curcumin-loaded ethosomes (Cur@ES). In-vitro transdermal experiments demonstrated that Cur@TES significantly increased the amount of drug retained in the skin (P＜0.05). Fluorescence imaging confirmed that the skin distribution were distinctly enhanced with the delivery by TPGS mediated transethosomes. In addition, Cur@TES showed a significant inhibitory effect on Inflammatory swelling in the mouse ear-swelling model. TPGS-mediated transethosomes exhibit significant transdermal advantages and enhanced anti-inflammatory effects, providing a new perspective for the transdermal delivery of curcumin.

Rapamycin protects mouse skin from ultraviolet B-induced photodamage by modulating Hspb2-mediated autophagy and apoptosis.

Continuous exposure to UVB is the main extrinsic cause of skin photodamage, which is associated with oxidative stress, DNA damage, apoptosis and degradation of collagen. Rapamycin, a mechanistic target inhibitor of rapamycin complex 1 (mTORC1), has been shown to play a crucial role anti-tumor and aging retardation, but its mechanism of action in UVB-induced photodamage still remains unknown. In this study, we investigated the role of rapamycin and Hspb2 (also known as Hsp27) in UVB-induced photodamage in mice. We constructed skin acute photodamage models on the ears of WT and Hspb2 KO mice, respectively, and administered rapamycin treatment. Histological results showed that knockout of the hspb2 exacerbated the skin damage, as evidenced by thickening of the epidermis, breakage and disruption of collagen fibers and reduction in their number, which is reversed by rapamycin treatment. In addition, hspb2 knockout promoted UVB-induced apoptosis and reduced autophagy levels, with a significant increase in p53 levels and Bax/Bcl-2 ratio, a reduction in LC3II/I ratio and an increase in p62 levels in the KO mice compared to those in WT mice after the same dose of UVB irradiation. Rapamycin was also found to inhibit collagen degradation induced by hspb2 knockdown through activation of the TGF-β/Smad signaling pathway. Rapamycin can alleviate skin photodamage from Hspb2 knockout to some extent. It may be a potential therapeutic drug for skin photodamage. In this study, we investigated the role of rapamycin and Hspb2 in UVB-induced photodamage in mice. Histological results showed that knockout of the hspb2 exacerbated the skin damage, as evidenced by thickening of the epidermis, breakage and disruption of collagen fibers and reduction in their number, which is reversed by rapamycin treatment. In addition, hspb2 knockout promoted UVB-induced apoptosis and reduced autophagy levels. Rapamycin was also found to inhibit collagen degradation induced by hspb2 knockdown through activation of the TGF-β/Smad signaling pathway. We conclude that rapamycin and Hspb2 exert a synergistic protective effect in skin photodamage.

The antibacterial activity of berberine against Cutibacterium acnes: its therapeutic potential in inflammatory acne.

Cutibacterium acnes (C. acnes) is a major pathogen implicated in the evolution of acne inflammation. Inhibition of C. acnes-induced inflammation is a prospective acne therapy strategy. Berberine (BBR), a safe and effective natural ingredient, has been proven to exhibit powerful antimicrobial and anti-inflammatory properties. However, the antimicrobial effect of BBR against C. acnes and its role in C. acnes-mediated inflammatory acne have not been explored. The objective of this investigation was to assess the antibacterial activity of BBR against C. acnes and its inhibitory effect on the inflammatory response. The results of in vitro experiments showed that BBR exhibited significant inhibition zones against four C. acnes strains, with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in the range of 6.25-12.5 μg/mL and 12.5-25 μg/mL, respectively. On the bacterial growth curve, the BBR-treated C. acnes exhibited obvious growth inhibition. Transmission electron microscopy (TEM) images indicated that BBR treatment resulted in significant morphological changes in C. acnes. High-content imaging analysis further confirmed that BBR could effectively inhibit the proliferation of C. acnes. The disruption of cell wall and cell membrane structure by BBR treatment was preliminary confirmed according to the leakage of cellular contents such as potassium (K+), magnesium (Mg2+), and alkaline phosphatase (AKP). Furthermore, we found that BBR could reduce the transcript levels of genes associated with peptidoglycan synthesis (murC, murD, mraY, and murG). Meanwhile, we investigated the modulatory ability of BBR on C. acnes-induced skin inflammation in mice. The results showed that BBR effectively reduced the number of C. acnes colonized in mice's ears, thereby alleviating ear swelling and erythema and significantly decreasing ear thickness and weight. In addition, BBR significantly decreased the levels of pro-inflammatory cytokines IL-6, IL-1β, and TNF-α in auricular tissues. These results suggest that BBR has the potential to treat inflammatory acne induced by C. acnes.

Large-field-of-view optical-resolution optoacoustic microscopy using a stationary silicon-photonics acoustic detector.

Optical-resolution optoacoustic microscopy (OR-OAM) enables label-free imaging of the microvasculature by using optical pulse excitation and acoustic detection, commonly performed by a focused optical beam and an ultrasound transducer. One of the main challenges of OR-OAM is the need to combine the excitation and detection in a coaxial configuration, often leading to a bulky setup that requires physically scanning the ultrasound transducer to achieve a large field of view. The aim of this work is to develop an OR-OAM configuration that does not require physically scanning the ultrasound transducer or the acoustic beam path. Our OR-OAM system is based on a non-coaxial configuration in which the detection is performed by a silicon-photonics acoustic detector (SPADE) with a semi-isotropic sensitivity. The system is demonstrated in both epi- and trans-illumination configurations, where in both configurations SPADE remains stationary during the imaging procedure and only the optical excitation beam is scanned. The system is showcased for imaging resolution targets and for the in vivo visualization of the microvasculature in a mouse ear. Optoacoustic imaging with focal spots down to , lateral resolution of , and a field of view higher than 4mm in both lateral dimensions were demonstrated. We showcase a new OR-OAM design, compatible with epi-illumination configuration. This setup enables relatively large fields of view without scanning the acoustic detector or acoustic beam path. Furthermore, it offers the potential for high-speed imaging within compact, miniature probe and could potentially facilitate the clinical translation of OR-OAM technology.

Investigation of inflammatory mechanisms induced by croton oil in mouse ear

Croton oil is liquid at room temperature, with a pale-yellow color and spicy odor. It is commonly used in combination with phenol as a chemical peeling agent in dermatology, which reveals its caustic exfoliating effects. Topical use of croton oil at a high dose produces skin irritation, inflammation, swelling, pain, and even tumors. Therefore, croton oil has been widely used for inflammation, pain, and tumor related research, with different animal models having been established. However, mechanistic studies through which croton oil induces skin swelling, injury and activates tissue repair/regeneration are limited. The present study used croton oil to induce mouse ear edema and examined tissue responses 4 h after exposure. To this end, croton oil was applied to the ventral side of mouse ears, followed by tissue collection. Samples were analyzed by hematoxylin and eosin (H&E) staining, toluidine blue staining, and immunohistochemistry staining for myeloperoxidase (MPO) and matrix metalloproteinase-9 (MMP-9). Western blotting and ELISA were also carried out for MMP-9 together with unbiased proteomic analysis using mass-spectrometry. Results from our study demonstrated that as soon as 4 h of exposure to 2.5 % croton oil, the expression levels of MPO and MMP-9 in the dermis significantly increased compared to acetone-treated (vehicle) control ears, as did other inflammatory reactions such as swelling and neutrophil aggregation and infiltration. Subsequently, proteomic analysis confirmed that croton oil treatment resulted in significant upregulation of proteins such as myeloperoxidase (MPO), matrix metalloproteinase-9 (MMP-9), and matrix metalloproteinase-8 (MMP-8) in the ear skin. Interestingly, mouse ears treated with acetone vehicle showed differential expression of 2,478 proteins relative to naïve tissues; among those differentially expressed in acetone-treated samples were members of the phosphatidylinositol-glycan biosynthesis class N, T and U proteins (PIGN, PIGT, and PIGU). Overall, this work confirms the presence of neutrophil-derived MPO and MMP-9 and extends the body of knowledge to show that MMP-8 is also present during croton oil-mediated skin inflammation in the mouse ear; moreover, we find that acetone vehicle is not inert and has effects on the skin that should be considered moving forward.

Label-Free Non-Contact Vascular Imaging using Photon Absorption Remote Sensing.

Functional vascular imaging is a critical method for early detection and prevention of disease. Established non-contact vascular imaging techniques capture predominantly structural information. In this study, a novel non-contact label-free in vivo Photon Absorption Remote Sensing (PARS) microscope is developed for structural and functional vascular imaging. The presented in vivo PARS microscope captures the endogenous absorption of green (532nm) light to form a complete picture of vasculature and surrounding tissues. Imaging system repeatability is enhanced through robust transient absorption signal extraction, and state-of-the-art real-time alignment methods. Detailed imaging of vascular structure is demonstrated through in vivo microscopy of two established animal models: mouse ear and chicken embryo. Preliminary functional contrast is realized through video rate imaging of red blood cell dynamics in the capillary networks of chicken embryos. The presented in vivo PARS microscope successfully captures detailed structural and functional vascular contrast. This innovative non-contact label-free imaging technique holds promise as a tool for preventative medical care, as functional change often precedes structural change.

Raepenol™ Cream, a Complex of Natural Compounds, Promotes Wound Healing and Relieves Pruritus In Vivo.

Skin wound healing is a physiological process restoring the structural and functional integrity of injured skin. During this process, wound management preventing bacterial infection and complications is important for the regeneration of skin layers and adnexa, as well as the protective function of the skin. Therefore, the development of an effective ointment to promote wound healing without complications is beneficial. This study developed Raepenol™ cream, comprising a base cream and natural compounds including paeonol, D-panthenol and extract of Centella asiatica, and assessed its therapeutic effect in wound healing. A rat model of skin wound healing and a mouse model of imiquimod-induced pruritus were employed. The effect of Raepenol™ cream was evaluated by wound size and histological analysis, including the integrity of skin structures and inflammatory response. Raepenol™ cream treatment effectively restored the structural integrity of the skin in rats, including wound closure, regeneration of skin adnexa, and reconstitution of collagen, comparable to commercial ointment. Additionally, Raepenol™ cream significantly suppressed pruritus by inhibiting mast cell infiltration or retention in the inflammatory site of mouse ears. Raepenol™ cream effectively promoted wound healing and relieved pruritus in animal models. These results suggest that it could be a promising option for wound care and pruritus relief, offering potential advantages over current ointments.

Novel oxicam nonsteroidal compound XK01 attenuates inflammation by suppressing the NF-κB and MAPK pathway in RAW264.7 macrophages

Traditional non-steroidal anti-inflammatory drugs (NSAIDs) show serious adverse effects during clinical use, which limits their usage. Oxicams (e.g., piroxicam, meloxicam) are widely used as NSAIDs. However, selectivity to cyclooxygenase (COX) 2 may cause cardiovascular problems considering the long-term use of the drugs. Therefore, it is important to develop new non-steroidal compounds as anti-inflammatory drugs. In the present study, we evaluated the anti-inflammatory activity of a newly developed nonsteroidal drug XK01. Our data showed that XK01 reduced the contents of nitric oxide (NO) and reactive oxygen species (ROS)and inhibited the transcription levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1β in a dose-dependent manner in lipopolysaccharide (LPS)-stimulated mouse RAW264.7 macrophages. XK01 showed no significant inhibitory effect on COX-1, but inhibited the expression of COX-2. At molecular level, XK01 prevented the translocation of p65 protein from the cytoplasm to the nucleus and inhibited the phosphorylation of p65, IκB, and MAPKs proteins. And high concentration of XK01 also inhibited the phosphorylation of JNK, p38 and ERK, showing stronger effect than that of meloxicam. In addition, the anti-inflammatory activity of XK01 was further validated in Xylene-induced mouse ear swelling model. Thus, this study verified that XK01 inhibits the expression of inflammatory mediators and COX-2, and exhibits potential anti-inflammatory effects via suppressing the NF-κB and MAPK pathway.

Optical and ultrasonic dual-sensitive sensor and its application in photoacoustic microscopy

Multi-modality imaging is significant for biomedical applications. We propose a dual-sensitive sensor to simultaneously detect optical and ultrasonic signals. Based upon the classical piezoelectric structure, we attach a photosensitive layer made of carbon nanotubes-polydimethylsiloxane (CNTs-PDMS) composite to the surface. The photosensitive layer absorbs light and converts it into ultrasound, while allowing acoustic energy to transmit through concurrently. After optimizing the ratio of PDMS to CNTs, we increase the sensor’s light detection sensitivity and maintain the ultrasound detection sensitivity. Finally, the successful implementation in mouse ear optical attenuation–photoacoustic imaging demonstrates the dual-sensitive sensor’s potential application in multi-modality imaging.

Pomegranate flower polysaccharide improves mastitis in mice by regulating intestinal flora and restoring the blood-milk barrier.

This study explored the inhibitory effect of pomegranate flower polysaccharide (PFPS) on mastitis through in vitro and in vivo models. PFPS is a new type of polysaccharide isolated and extracted from pomegranate flowers. The result revealed that PFPS consists of GalA, Ara, and Gal, and the residues consist of 1,4-GalpA, 1,4-Galp, and 1,3,6-Galp, which contain HG-type and RG-I-type pectin structural domains. In vitro studies showed that PFPS could inhibit LPS-enhanced phagocytosis of RAW 264.7 cells and the release of IL-1β, IL-10, and TNF-α. In vivo, studies showed that PFPS improved xylene-induced mouse ear swelling and carrageenan-induced mouse paw edema by inhibiting inflammatory factors. In the mouse mastitis model, PFPS significantly improved LPS-induced inflammation and oxidative stress in mammary tissue. Intestinal flora sequencing results showed that PFPS could effectively regulate the intestinal flora of mice, reduce the relative abundance of pathogenic bacteria Oscillospira and AF12, and increase the probiotics Blautia, Parabacteroides, Allobaculum, and Clostridiaceae_Clostridium. Therefore, PFPS ultimately played a role in preventing mastitis by regulating the intestinal flora and further improving the blood-milk barrier. This study provides a scientific basis for PFPS as a potential candidate drug for the treatment of mastitis.