Melanopsin retinal ganglion cells mediate light-promoted brain development.

During development, melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) become light sensitive much earlier than rods and cones. IpRGCs project to many subcortical areas, whereas physiological functions of these projections are yet to be fully elucidated. Here, we found that ipRGC-mediated light sensation promotes synaptogenesis of pyramidal neurons in various cortices and the hippocampus. This phenomenon depends on activation of ipRGCs and is mediated by the release of oxytocin from the supraoptic nucleus (SON) and the paraventricular nucleus (PVN) into cerebral-spinal fluid. We further characterized a direct connection between ipRGCs and oxytocin neurons in the SON and mutual projections between oxytocin neurons in the SON and PVN. Moreover, we showed that the lack of ipRGC-mediated, light-promoted early cortical synaptogenesis compromised learning ability in adult mice. Our results highlight the importance of light sensation early in life on the development of learning ability and therefore call attention to suitable light environment for infant care.

YjgA plays dual roles in enhancing PTC maturation.

Ribosome biogenesis is a highly regulated cellular process that involves the control of numerous assembly factors. The small protein YjgA has been reported to play a role in the late stages of 50S assembly. However, the precise molecular mechanism underlying its function remains unclear. In this study, cryo-electron microscopy (cryo-EM) structures revealed that depletion of YjgA or its N-terminal loop in Escherichia coli both lead to the accumulation of immature 50S particles with structural abnormalities mainly in peptidyl transferase center (PTC) and H68/69 region. CryoDRGN analysis uncovered 8 and 6 distinct conformations of pre50S for ΔyjgA and YjgA-ΔNloop, respectively. These conformations highlighted the role of the N-terminal loop of YjgA in integrating uL16 and stabilizing H89 in PTC, which was further verified by the pull-down assays of YjgA and its mutants with uL16. Together with the function of undocking H68 through the binding of its C-terminal CTLH-like domain to the base of the L1 stalk, YjgA facilitates the maturation of PTC. This study identified critical domains of YjgA contributing to 50S assembly efficiency, providing a comprehensive understanding of the dual roles of YjgA in accelerating ribosome biogenesis and expanding our knowledge of the intricate processes governing cellular protein synthesis.

Hybrid Palladium-Catalyzed Intramolecular Carboamination of Conjugated Dienes: Synthesis of Functionalized Pyrrolidines via Selective Trifluoromethylarene Defluorination.

The incorporation of difluoromethylene groups into aza-heterocycles represents a compelling yet underexplored avenue in contemporary chemical research. In this study, we unveil a hybrid palladium-catalyzed intramolecular gem-difluoroalkylamination of conjugated dienes, providing a versatile approach to the synthesis of diverse functionalized pyrrolidines. Noteworthy features include mild reaction conditions and a remarkable tolerance toward various functional groups. Additionally, the use of alkyl iodides as electrophiles facilitates the generation of the corresponding alkylamination products. Control experiments support a proposed hybrid palladium-catalyzed radical-polar crossover pathway, offering insights into the underlying chemical processes governing this transformation.

ZFP804A mutant mice display sex-dependent schizophrenia-like behaviors.

Genome-wide association studies uncovered the association of ZNF804A (Zinc-finger protein 804A) with schizophrenia (SZ). In vitro data have indicated that ZNF804A might exert its biological roles by regulating spine and neurite morphogenesis. However, no in vivo data are available for the role of ZNF804A in psychiatric disorders in general, SZ in particular. We generated ZFP804A mutant mice, and they showed deficits in contextual fear and spatial memory. We also observed the sensorimotor gating impairment, as revealed by the prepulse inhibition test, but only in female ZFP804A mutant mice from the age of 6 months. Notably, the PPI difference between the female mutant and control mice was no longer existed with the administration of Clozapine or after the ovariectomy. Hippocampal long-term potentiation was normal in both genders of the mutant mice. Long-term depression was absent in male mutants, but facilitated in the female mutants. Protein levels of hippocampal serotonin-6 receptor and GABAB1 receptor were increased, while those of cortical dopamine 2 receptor were decreased in the female mutants with no obvious changes in the male mutants. Moreover, the spine density was reduced in the cerebral cortex and hippocampus of the mutant mice. Knockdown of ZFP804A impaired the neurite morphogenesis of cortical and hippocampal neurons, while its overexpression enhanced neurite morphogenesis only in the cortical neurons in vitro. Our data collectively support the idea that ZFP804A/ZNF804A plays important roles in the cognitive functions and sensorimotor gating, and its dysfunction may contribute to SZ, particularly in the female patients.

DNA ligase IV dificiency with elevated serum IgG levels suspected to have myelodysplastic syndrome: a case report.

BACKGROUND: Ligase IV (LIG4) dificiency is a very rare clinical syndrome with around 50 cases reported to date. This syndrome is caused by biallelic pathogenic variants in the LIG4 gene, which cause DNA damage repair disorders, mainly manifesting as severe immunodeficiency. CASE PRESENTATION: We report the case of a 15-month-old male child with pancytopenia, growth retardation, microcephaly, history of vaccine-related rubella, elevated immunoglobulin G, and decreased T- and B lymphocytes. Next-generation sequencing revealed LIG4 pathogenic genes and compound heterozygous mutations, namely the missense mutation c.833G > T (p.Arg278Leu) and deletion mutation c.1271_1275del (p.Lys424Argfs*20). CONCLUSION: This case suggests that LIG4 dificiency can manifest not only as immunodeficiency but also with increased serum IgG levels and pancytopenia, which constitutes an additional clinical phenotype. Furthermore, this case suggests that LIG4 deficiency should be considered upon differential diagnosis of myelodysplastic syndrome in children.

Thin Plasma-Polymerized Coatings as a Primer with Polyurethane Topcoat for Improved Corrosion Resistance.

Use of a plasma-polymerized (pp) layer under a polyurethane (PU) coating on aluminum dramatically improves the corrosion resistance. Compared to conventional polymer coatings, pp coatings are highly cross-linked, have better adhesion to substrates, and result in lower emission of volatile organic contents. Although past research has focused on the properties of comparatively thick pp films and on the use of pp films alone to protect metals, we consider here very thin pp coatings as a primer layer to improve corrosion resistance. Electrochemical impedance spectroscopy combined with salt spray lab tests show that the corrosion resistance of a PU coating on top of a pp coating from hexamethyldisiloxane (HMDSO) is much better than that of a PU coating directly on Al 3003. The relatively poor pull-off adhesion between PU and pp-HMDSO is readily addressed using a gradient coating by depositing a pp maleic anhydride layer over the pp-HMDSO coating or by modifying the surface composition of the pp-HMDSO coating with N2 plasma. X-ray photon spectroscopy analysis of the failure interface from pull-off tests makes clear that failure does not occur at the interface between the pp coating and the metal substrate. Field tests show the performance of the coating system with PU on a gradient coating on Al 3003 to be superior to that of a coating system of PU on chromate-treated Al 3003.

The Small GTPase Rac1 Contributes to Extinction of Aversive Memories of Drug Withdrawal by Facilitating GABAA Receptor Endocytosis in the vmPFC.

Extinction of aversive memories has been a major concern in neuropsychiatric disorders, such as anxiety disorders and drug addiction. However, the mechanisms underlying extinction of aversive memories are not fully understood. Here, we report that extinction of conditioned place aversion (CPA) to naloxone-precipitated opiate withdrawal in male rats activates Rho GTPase Rac1 in the ventromedial prefrontal cortex (vmPFC) in a BDNF-dependent manner, which determines GABAA receptor (GABAAR) endocytosis via triggering synaptic translocation of activity-regulated cytoskeleton-associated protein (Arc) through facilitating actin polymerization. Active Rac1 is essential and sufficient for GABAAR endocytosis and CPA extinction. Knockdown of Rac1 expression within the vmPFC of rats using Rac1-shRNA suppressed GABAAR endocytosis and CPA extinction, whereas expression of a constitutively active form of Rac1 accelerated GABAAR endocytosis and CPA extinction. The crucial role of GABAAR endocytosis in the LTP induction and CPA extinction is evinced by the findings that blockade of GABAAR endocytosis by a dynamin function-blocking peptide (Myr-P4) abolishes LTP induction and CPA extinction. Thus, the present study provides first evidence that Rac1-dependent GABAAR endocytosis plays a crucial role in extinction of aversive memories and reveals the sequence of molecular events that contribute to learning experience modulation of synaptic GABAAR endocytosis.SIGNIFICANCE STATEMENT This study reveals that Rac1-dependent GABAAR endocytosis plays a crucial role in extinction of aversive memories associated with drug withdrawal and identifies Arc as a downstream effector of Rac1 regulations of synaptic plasticity as well as learning and memory, thereby suggesting therapeutic targets to promote extinction of the unwanted memories.

In Situ Nanoscale Characterization of Water Penetration through Plasma Polymerized Coatings.

The search continues for means of making quick determinations of the efficacy of a coating for protecting a metal surface against corrosion. One means of reducing the time scale needed to differentiate the performance of different coatings is to draw from nanoscale measurements inferences about macroscopic behavior. Here we connect observations of the penetration of water into plasma polymerized (PP) protective coatings and the character of the interface between the coating and an oxide-coated aluminum substrate or model oxide-coated silicon substrate to the macroscopically observable corrosion for those systems. A plasma polymerized film from hexamethyldisiloxane (HMDSO) monomer is taken as illustrative of a hydrophobic coating, while a PP film from maleic anhydride (MA) is used as a characteristically hydrophilic coating. The neutron reflectivity (NR) of films on silicon oxide coated substrates shows that water moves more readily through the hydrophilic PP-MA film. Off-specular X-ray scattering indicates the PP-MA film on aluminum is less conformal with the substrate than is the PP-HMDSO film. Measurements with infrared-visible sum frequency generation spectroscopy (SFG), which probes the chemical nature of the interface, make clear that the chemical interactions between coating and aluminum oxide are disrupted by interfacial water. With this water penetration and interface disruption, macroscopic corrosion can occur much more rapidly. An Al panel coated with PP-MA corrodes after 1 day in salt spray, while a similarly thin (∼30 nm) PP-HMDSO coating protects an Al panel for a period on the order of one month.

Discs large homolog 5 decreases formation and function of invadopodia in human hepatocellular carcinoma via Girdin and Tks5.

Invadopodium formation is a crucial early event of invasion and metastasis of hepatocellular carcinoma (HCC). However, the molecular mechanisms underlying regulation of invadopodia remain elusive. This study aimed to investigate the potential role of discs large homolog 5 (Dlg5) in invadopodium formation and function in HCC. We found that Dlg5 expression was significantly lower in human HCC tissues and cell lines than adjacent nontumor tissues and liver cells. Lower Dlg5 expression was associated with advanced stages of HCC, and poor overall and disease-free survival of HCC patients. Dlg5-silencing promoted epithelial-mesenchymal transition, invadopodium formation, gelatin degradation function, and invadopodium-associated invasion of HepG2 cells. In contrast, Dlg5 overexpression inhibited epithelial-mesenchymal transition, functional invadopodium formation, and invasion of SK-Hep1 cells. Both Girdin and Tks5, but not the Tks5 nonphosphorylatable mutant, were responsible for the enhanced invadopodium formation and invasion of Dlg5-silenced HepG2 cells. Furthermore, Dlg5 interacted with Girdin and interfered with the interaction of Girdin and Tks5. Dlg5 silencing promoted Girdin and Tks5 phosphorylation, which was abrogated by Girdin silencing and rescued by inducing shRNA-resistant Girdin expression. Moreover, Dlg5 overexpression significantly inhibited HCC intrahepatic and lung metastasis in vivo. Taken together, our data indicate that Dlg5 acts as a novel regulator of invadopodium-associated invasion via Girdin and by interfering with the interaction between Girdin and Tks5, which might be important for Tks5 phosphorylation in HCC cells. Conceivably, Dlg5 may act as a new biomarker for prognosis of HCC patients.

Abnormal levels of seven amino neurotransmitters in depressed rat brain and determination by HPLC-FLD.

The determination of amino acids with actions like neurotransmitters or modulators has been increasingly important for diagnosis in many neuropsychiatric diseases. A rapid and simple high-performance liquid chromatography with fluorescence detection method was developed for simultaneous determination of seven amino acids: aspartate (Asp), glutamate (Glu), serine (Ser), glutamine (Gln), glycine (Gly), taurine (Tau) and γ-aminobutyric` acid (GABA). Homoserine was used as an internal standard. The analysis was performed on a BDS column with methanol and 50 mm sodium acetate solution (pH 6.5) using a simple gradient elution. Several parameters of the developed method were validated including linearity, accuracy, precision, extraction recovery and stability, which were within the acceptable range. The method was successfully applied to determination of real samples: hippocampus and cortex in depressed rats exposed to chronically unpredictable stress in order to study if there existed differences in the seven amino acids levels between depressed rats and control. The results showed that Asp, Gly, Tau and GABA significantly decreased with increasing Gln in the hippocampus of depressed rats, compared with that of the control group, among which obviously lower level of Asp and higher level of Gln in cortex were observed. The analytical method and the results could be useful for clinical diagnosis and further insight into pathophysiological mechanism of depression.

Nanocapsule assemblies as effective enzyme delivery systems against hyperuricemia.

The uricase nanocapsule assemblies (UNAs) were developed as effective delivery systems against hyperuricemia following parenteral enzyme therapy. UNAs were characterized in terms of micromorphology, size, catalytic activity, stability, and enzymatic kinetics. The pharmacokinetics/pharmacodynamics in rats after intravenous or subcutaneous injection was investigated. Immunogenicity, hemolysis and stimulation were determined. UNA was composed of many nanocapsules, and thus had higher loading efficiencies and stabilities than a single nanocapsule. The uricase molecules entrapped inside nanocapsules were separated from the circulating bloodstream to retain catalytic activities for a longer time than free uricase. UNAs increased the bioavailability and uric acid-lowering efficacy of uricase, while the immunogenicity and hemolysis rate of uricase were decreased. The superior properties of UNAs might be ascribed to the favorable conformational changes of uricase. Nanocapsule assemblies appeared to be able to deliver uricase effectively. This study also highlighted the importance of suitable systems for therapeutic enzyme delivery.

The bidirectional effects of hypothyroidism and hyperthyroidism on anxiety- and depression-like behaviors in rats.

Thyroid hormone disorders have long been linked to depression, but the causal relationship between them remains controversial. To address this question, we established rat models of hypothyroidism using (131)iodine ((131)I) and hyperthyroidism using levothyroxine (LT4). Serum free thyroxine (FT4) and triiodothyronine (FT3) significantly decreased in the hypothyroid of rats with single injections of (131)I (5mCi/kg). These rats exhibited decreased depression-like behaviors in forced swimming test and sucrose preference tests, as well as decreased anxiety-like behaviors in an elevated plus maze. Diminished levels of brain serotonin (5-HT) and increased levels of hippocampal brain-derived neurotrophic factor (BDNF) were found in the hypothyroid rats compared to the control saline-vehicle administered rats. LT4 treatment reversed the decrease in thyroid hormones and depression-like behaviors. In contrast, hyperthyroidism induced by weekly injections of LT4 (15µg/kg) caused a greater than 10-fold increase in serum FT4 and FT3 levels. The hyperthyroid rats exhibited higher anxiety- and depression-like behaviors, higher brain 5-HT level, and lower hippocampal BDNF levels than the controls. Treatment with the antidepressant imipramine (15mg/kg) diminished serum FT4 levels as well as anxiety- and depression-like behaviors in the hyperthyroid rats but led to a further increase in brain 5-HT levels, compared with the controls or the hypothyroid rats. Together, our results suggest that hypothyroidism and hyperthyroidism have bidirectional effects on anxiety- and depression-like behaviors in rats, possibly by modulating hippocampal BDNF levels.

Impaired contextual fear extinction and hippocampal synaptic plasticity in adult rats induced by prenatal morphine exposure.

Prenatal opiate exposure causes a series of neurobehavioral disturbances by affecting brain development. However, the question of whether prenatal opiate exposure increases vulnerability to memory-related neuropsychiatric disorders in adult offspring remains largely unknown. Here, we found that rats prenatally exposed to morphine (PM) showed impaired acquisition but enhanced maintenance of contextual fear memory compared with control animals that were prenatally exposed to saline (PS). The impairment of acquisition was rescued by increasing the intensity of footshocks (1.2 mA rather than 0.8 mA). Meanwhile, we also found that PM rats exhibited impaired extinction of contextual fear, which is associated with enhanced maintenance of fear memory. The impaired extinction lasted for 1 week following extinction training. Furthermore, PM rats exhibited reduced anxiety-like behavior in the elevated plus-maze and light/dark box test without differences in locomotor activity. These alterations in PM rats were mirrored by abnormalities in synaptic plasticity in the Schaffer collateral-CA1 synapses of the hippocampus in vivo. PS rats showed blocked long-term potentiation and enabled long-term depression in CA1 synapses following contextual fear conditioning, while prenatal morphine exposure restricted synaptic plasticity in CA1 synapses. The smaller long-term potentiation in PM rats was not further blocked by contextual fear conditioning, and the long-term depression enabled by contextual fear conditioning was abolished. Taken together, our results provide the first evidence suggesting that prenatal morphine exposure may increase vulnerability to fear memory-related neuropsychiatric disorders in adulthood.

Photogenerated outer electric field induced electrophoresis of organic nanocrystals for effective solid-solid photocatalysis.

Rapid mass transfer in solid-solid reactions is crucial for catalysis. Although phoretic nanoparticles offer potential for increased collision efficiency between solids, their implementation is hindered by limited interaction ranges. Here, we present a self-driven long-range electrophoresis of organic nanocrystals facilitated by a rationally designed photogenerated outer electric field (OEF) on their surface. Employing perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecular nanocrystals as a model, we demonstrate that a directional OEF with an intensity of 13.6-0.4 kV m-1 across a range of 25-200 µm. This OEF-driven targeted electrophoresis of PTCDA nanocrystals onto the microplastic surface enhances the activity for subsequent decomposition of microplastics (196.8 mg h-1) into CO2 by solid-solid catalysis. As supported by operando characterizations and theoretical calculations, the OEF surrounds PTCDA nanocrystals initially, directing from the electron-rich (0 1 1) to the hole-rich [Formula: see text] surface. Upon surface charge modulation, the direction of OEF changes toward the solid substrate. The OEF-driven electrophoretic effect in organic nanocrystals with anisotropic charge enrichment characteristics indicates potential advancements in realizing effective solid-solid photocatalysis.

A multimodal therapy for infected diabetic wounds based on glucose-responsive nanocomposite-integrated microneedles.

Diabetic wounds in a state of high glucose are refractory to treatment and healing, especially if they are infected with bacteria. Herein, a novel nanocomposite (CIP/GOx@ZIF-8) was synthesized by loading ciprofloxacin hydrochloride (CIP) and glucose oxidase (GOx) into zeolitic imidazole framework-8 (ZIF-8) that exhibited good glucose sensitivity and catalytic activity. The high glucose in diabetic wounds could be decomposed into hydrogen peroxide (H2O2) and gluconic acid via the catalysis of GOx, which further destroyed CIP/GOx@ZIF-8 to release Zn2+ and cargos. The combination of glucose starvation, Zn2+, H2O2 and CIP could elevate the antibacterial effect and reduce bacterial resistance. Subsequently, the nanocomposite was fabricated into dissolving microneedles (CIP/GOx@ZIF-8 MNs) using polyvinylpyrrolidone (PVP). The microneedles exhibited good mechanical strength, puncture performance, dissolving performance, glucose responsiveness, antibacterial performance and biocompatibility. For in vivo wound healing, CIP/GOx@ZIF-8 MNs with good biosafety facilitated neovascularization and collagen deposition as well as reduced inflammation, and the wounds were almost healed after treatment. This multimodal therapeutic strategy is created to provide a unique treatment for infected diabetic wounds.

In situ growth of self-supported CuO nanorods from Cu-MOFs for glucose sensing and elucidation of the sensing mechanism.

Herein, we present a simple and mild method to in situ prepare CuO nanostructures for non-enzymatic glucose sensing. A Cu-metal organic framework (Cu-MOF) precursor was first directly grown on a pencil lead electrode with 3D graphene-like surfaces (EPLE) and then in situ transformed into CuO nanorods. The CuO nanorod-modified EPLE (CuO/EPLE) shows high sensitivity (1138.32 µA mM-1 cm-2), fast response time (1.5 s) and low detection limit (0.11 µM) for glucose oxidation. It has been found that NaOH promoted the generation of ˙OH groups and Cu(III) on the CuO surface, which then facilitated the electrochemical oxidation of glucose. Signals characteristic of hydroxyl and carbon-centered radical adducts were detected by EPR. Furthermore, the CuO/EPLE sensor also shows good accuracy in glucose determination in human serum samples.

Selective 1,4-syn-Addition to Cyclic 1,3-Dienes via Hybrid Palladium Catalysis.

1,4-cis-Disubstituted cyclic compounds play a pivotal role in pharmaceutical development, offering enhanced potency and bioavailability. However, their stereoselective and modular synthesis remains a long-standing challenge. Here, we report an innovative strategy for accessing these structures via mild conditions employing cyclic 1,3-dienes/alkyl(aryl)halides and amines. This procedure exhibits a wide substrate scope that tolerates various functional groups. The utility of this method is demonstrated in the efficient synthesis of a TRPV6 inhibitor, CFTR modulator, and other bioactive molecules. Combined experimental and computational studies suggest that the hybrid palladium-catalyzed radical-polar crossover mechanism is crucial for achieving exceptional 1,4-syn-addition selectivity (dr > 20:1).

Research progress of ubiquitin and ubiquitin-like signaling in Toxoplasma gondii.

Toxoplasmosis, a zoonotic parasitic disease caused by Toxoplasma gondii (T. gondii), is prevalent worldwide. The fact should be emphasized that a considerable proportion of individuals infected with T. gondii may remain asymptomatic; nevertheless, the condition can have severe implications for pregnant women or immunocompromised individuals. The current treatment of toxoplasmosis primarily relies on medication; however, traditional anti-toxoplasmosis drugs exhibit significant limitations in terms of efficacy, side effects, and drug resistance. The life cycles of T. gondii are characterized by distinct stages and its body morphology goes through dynamic alterations during the growth cycle that are intricately governed by a wide array of post-translational modifications (PTMs). Ubiquitin (Ub) signaling and ubiquitin-like (Ubl) signaling are two crucial post-translational modification pathways within cells, regulating protein function, localization, stability, or interactions by attaching Ub or ubiquitin-like proteins (Ubls) to target proteins. While these signaling mechanisms share some functional similarities, they have distinct regulatory mechanisms and effects. T. gondii possesses both Ub and Ubls and plays a significant role in regulating the parasite's life cycle and maintaining its morphology through PTMs of substrate proteins. Investigating the role and mechanism of protein ubiquitination in T. gondii will provide valuable insights for preventing and treating toxoplasmosis. This review explores the distinctive characteristics of Ub and Ubl signaling in T. gondii, with the aim of inspiring research ideas for the identification of safer and more effective drug targets against toxoplasmosis.

Actin polymerization-dependent increase in synaptic Arc/Arg3.1 expression in the amygdala is crucial for the expression of aversive memory associated with drug withdrawal.

Aversive memories associated with drug withdrawal may contribute to persistent drug seeking. Molecular mechanisms that are critical for aversive memory formation have yet to be elucidated. Recently, we showed in a rat conditioned place aversion (CPA) model that synaptic actin polymerization in the amygdala were required for aversive memory information. Here, we demonstrated that actin polymerization within the amygdala triggered transportation of activity-regulated cytoskeletal-associated protein (Arc/Arg3.1) into amygdalar synapses. Increased synaptic Arc/Arg3.1 expression contributed to aversive memory formation by regulating synaptic AMPA receptor (AMPAR) endocytosis, as in vivo knockdown of amygdalar Arc/Arg3.1 with Arc/Arg3.1-shRNA prevented both AMPAR endocytosis and CPA formation. We also demonstrated that conditioned morphine withdrawal led to induction of LTD in the amygdala through AMPAR endocytosis. We further demonstrated that Arc/Arg3.1-regulated AMPAR endocytosis was GluR2 dependent, as intra-amygdala injection of Tat-GluR2(3Y), a GluR2-derived peptide that has been shown to specifically block regulated, but not constitutive, AMPAR endocytosis, prevented AMPAR endocytosis, LTD induction, and aversive memory formation. Therefore, this study extends previous studies on the role of actin polymerization in synaptic plasticity and memory formation by revealing the critical molecular events involved in aversive memory formation as well as LTD induction, and by showing that Arc/Arg3.1 is a crucial mediator for actin polymerization functions, and, thus, underscores the unknown details of how actin polymerization mediates synaptic plasticity and memory.

Collagen-Based Dissolving Microneedles with Flexible Pedestals: A Transdermal Delivery System for Both Anti-Aging and Skin Diseases.

Biocompatible polymer microneedles (MNs) are emerging as a promising platform for transdermal drug delivery, especially for facial treatments. Therefore, an MN patch in this study uses hydrolyzed collagen (HC) contained in skin cells as the main raw material and adopts a two-step cast method to develop a rapidly dissolving microneedle (DMN) to deliver collagen in a simple and minimally invasive way, allowing the release of the encapsulated drug in the skin. By optimizing the formulation and proportion of HC and auxiliary support materials, the mechanical strength required to pierce the skin is obtained, while the soft pedestal allows for flexibility in application. The DMNs can dissolve completely in the skin within 15 min and release within ≈ 8 h, and do not cause toxicity or irritation when being applied. In contrast to the ineffectiveness of oral and external application, and the high risk of dermal injection, drug-loaded DMNs overcome the drawbacks of traditional methods with direct penetration and minimally invasive manner, enabling efficient and safe treatment. The successful preparation and research of HC DMNs have innovative and practical significance in this field, and it is expected to become a simple, effective, and popular transdermal drug delivery platform for cosmetics.