Background: Sarcopenia is an aging-related syndrome characterized by loss of skeletal muscle mass, strength, and function, with no approved pharmacological treatment. This study aimed to design, synthesize, and evaluate novel ML-167 derivatives for sarcopenia-associated muscle wasting. Methods: ML-167 derivatives were synthesized and characterized by [1]H NMR, [13]C NMR, and mass spectrometry. Biological activity was evaluated in C2C12 myoblasts using MTT and Western blot assays. Selected compounds were evaluated in a dexamethasone-induced muscle wasting model. Muscle strength, mass, biochemical parameters, and histopathology were assessed. Structure-activity relationships were analysed using cell viability, molecular docking, and ligand efficiency data, alongside physicochemical properties. Results: Compounds 6b (116%), 3a (115%), 8d (114%), 4c (112%), 3m (112%), and 3c (111%) showed the highest C2C12 viability at 1 μM. Compounds 3a, 3c, and 6b increased MyH3 expression by approximately 1.6-1.7-fold, while MyoG remained near basal levels. In vivo, these compounds improved muscle strength, mass, and biochemical parameters without overt hepatic or renal abnormalities based on assessed serum and histopathological findings. Among the evaluated derivatives, compound 6b emerged as the most promising overall lead candidate, showing the greatest improvement in skeletal muscle mass and metabolic parameters, whereas compound 3c demonstrated the strongest histopathological protection and favourable effects on muscle strength with favourable physicochemical properties. Molecular docking supported the SAR trends, although did not consistently correlate with cellular activity. Conclusions: The findings identify 3a, 3c, and 6b as promising lead compounds and support further investigation of ML-167 derivatives as potential pharmacological approaches for sarcopenia-associated muscle wasting.

Purpose: To evaluate the incidence, predictors, and clinical impact of treatment-emergent epiretinal membrane (ERM) in diabetic macular edema (DME) treated with dexamethasone implant, aflibercept, ranibizumab, bevacizumab, or faricimab. Methods: In this multicenter, retrospective, nonrandomized study, 501 eyes with center-involving DME were assessed and 423 eyes without ERM on pretreatment OCT and with 24-month follow-up were included. Eyes were classified by the intravitreal agent selected by the treating physician in routine care and maintained throughout follow-up; eyes requiring a drug switch or retinal laser/vitrectomy during follow-up were excluded. The last eligible pre-index SD-OCT confirmed the absence of ERM; BCVA, central subfield thickness (CST), and vitreomacular-interface (VMI) morphology were assessed at baseline and 6, 12, 18, and 24 months. Crude comparisons, multivariable logistic regression, and Kaplan-Meier/log-rank analyses were performed. Results: ERM developed in 36/423 eyes (8.5%). Incidence was 16.0% with dexamethasone implant, 7.5% with aflibercept, 7.7% with ranibizumab, 7.4% with bevacizumab, and 4.3% with faricimab. Dexamethasone implant showed higher ERM odds than pooled non-dexamethasone therapy after adjustment (OR 2.24, 95% CI 1.02-4.92; p = 0.044). Baseline VMI abnormality, severe NPDR/PDR, prior PRP, and higher baseline CST were also associated with ERM. Eyes developing ERM had smaller BCVA gains (+2.8 vs. +7.1 ETDRS letters; p < 0.001) and CST reductions (88.6 vs. 130.8 µm; p = 0.004). Conclusions: Treatment-emergent ERM was associated with baseline ocular characteristics and treatment category and with poorer 24-month outcomes. These observational drug-group signals require prospective confirmation.

Background/Objectives: Shape-memory biodegradable scaffolds (4D scaffolds) represent promising platforms for minimally invasive tissue engineering and localized drug delivery. This study investigated how two different fabrication techniques, electrospinning (ES) and extrusion-based direct ink writing (DIW), influence the structural, thermal, mechanical, shape-memory, and drug-release properties of poly(L-lactide-co-caprolactone) (PLA/PCL 70:30) scaffolds loaded with dexamethasone (DXM). Methods: DXM-loaded PLA/PCL 70:30 scaffolds were fabricated by ES and DIW. The resulting matrices were characterized in terms of morphology, mass, thickness, drug-loading efficiency, thermal properties by differential scanning calorimetry, shape-memory performance, tensile mechanical properties, and in vitro DXM release. Results: Both fabrication techniques produced DXM-loaded matrices with comparable mass and thickness and high loading efficiencies (>82%). Glass transition temperatures ranged between 33 and 39 °C, supporting thermally induced shape recovery under physiologically relevant conditions, while ES processing was associated with higher polymer crystallinity. All scaffolds exhibited shape-memory behavior, with recovery ratios exceeding 90%. ES scaffolds displayed a microporous nanofibrous architecture, whereas DIW scaffolds showed a more open and highly porous structure. These morphological differences were reflected in their mechanical behavior: ES scaffolds exhibited higher tensile strength (up to 16.5 MPa vs. 1.9 MPa) and elongation at break (up to 320% vs. 243%). Drug-release profiles were also fabrication-dependent, with ES scaffolds reaching a plateau at approximately 80% DXM release, whereas DIW scaffolds showed near-complete release within 48 h. Conclusions: Both fabrication approaches preserved the thermoresponsive shape-memory behavior of PLA/PCL 70:30 but generated distinct scaffold architectures that strongly influenced mechanical performance and DXM-release kinetics.

Background/Objectives: Poly(lactic-co-glycolic acid) (PLGA) microparticles are used for sustained drug delivery, yet their final quality depends on both initial droplet formation and the subsequent solvent-extraction-driven droplet-to-particle transition. Microfluidics provides excellent control over precursor droplets, but this control may be partially lost during particle formation. We previously developed dynamic solvent extraction (DSE), in which the droplet-to-particle transition occurs progressively during continuous transport through an extended microfluidic channel. Here, we investigated whether this control improves quality attributes and release of drug-loaded PLGA microparticles. Methods: Dexamethasone (DEX)-loaded PLGA microparticles were produced using DSE or static solvent extraction (SSE), in which microfluidic droplets were transferred to an external aqueous medium for particle formation. Three PLGA concentrations (2.5, 5, and 10% (w/v)) were investigated, with processing conditions selected to obtain comparable final particle sizes and reduce size as a confounding variable. Results: DSE significantly reduced particle-size coefficient of variation compared with SSE, indicating better preservation of size uniformity. Drug loading and encapsulation efficiency were governed mainly by PLGA concentration, with no significant effect of extraction strategy. Morphological effects were formulation-dependent, with the most pronounced defects in 5% (w/v) SSE particles. All formulations provided sustained DEX release over 70 days. Although the overall effect of extraction strategy on 24 h burst release was not statistically significant, DSE consistently produced numerically lower burst release, with the largest and most variable burst observed for the morphologically heterogeneous 5% (w/v) SSE formulation. Conclusions: These findings extend DSE to drug-loaded sustained-release microparticles and identify the solvent-extraction environment as an important determinant of final particle quality.

Background: Radiation maculopathy (RM) is a common complication after radiotherapy for intraocular tumors, causing permanent visual loss. Intravitreal dexamethasone (IV DEX) is effective for macular edema (ME) resolution, but functional outcomes remain highly heterogeneous. This study aimed to assess the prognostic utility of CEA classification on visual outcomes following IV DEX based on three parameters: largest cyst diameter (C), ellipsoid zone (EZ) disruption (E) and retinal pigment epithelium (RPE) atrophy (A). Methods: A retrospective analysis of 50 patients with RM secondary to Iodine-125 brachytherapy treated with IV DEX was performed. Best-corrected visual acuity (BCVA) and CEA parameters were analyzed with OCT before and after treatment. Results: IV DEX induced significant anatomical improvement (mean Δcyst: -203.3 μm, p < 0.001), regardless of functional response. Visual outcomes were related to baseline CEA stratification: eyes with intact outer retina gained +6.4 ETDRS letters (p = 0.002); eyes with EZ disruption demonstrated stability (-2.8 letters; p = 0.183); eyes with RPE atrophy significantly worsened (-11.7 letters; p = 0.014). Baseline RPE atrophy was the strongest negative predictor (p = 0.007). Subgroup analysis of patients with intact outer retina identified a baseline BCVA cutpoint of ≤70 letters to predict clinically significant visual improvement (≥5 letters), demonstrating a functional ceiling effect. Conclusions: The CEA classification effectively stratifies functional response in RM. EZ disruption and RPE atrophy identify eyes unlikely to achieve visual improvement despite a reduction in ME, aiding clinical decision-making and establishing functional expectations while promoting a fundamental shift from an edema-driven management to a biomarker-centered approach.

Immune cell trafficking among blood, lymphoid organs, and tissues is essential for homeostasis; however, the influence of environmental stressors on steady-state distribution remains unclear. Here we show that ambient cold stress (4 °C) and dexamethasone treatment induced systemic leukocytopenia, marked by the selective depletion of circulating B cells and reduced splenic mass. Viability assays confirmed that this loss was not due to cell death. Adoptive transfer of fluorescently labeled leukocytes revealed the directed redistribution of B cells into the bone marrow (BM). Regarding the mechanism, cold stress elevated corticosterone, which upregulated the homing receptor C-X-C chemokine receptor 4 (CXCR4) on peripheral B cells. Blocking CXCR4 with AMD3100 markedly impaired BM migration, establishing the pathway's functional necessity. This work proposed a model in which the BM acts as a transient immune reservoir during stress, conserving energy by sequestering B cells in a protected niche while prioritizing thermogenesis. This paradigm offers new insight into homeostatic immune regulation and potential therapeutic strategies for B-cell-mediated autoimmune disease.

Sustained postoperative anti-inflammatory therapy following intraocular surgery remains an unmet clinical need, as conventional topical corticosteroid eye drops suffer from poor bioavailability, patient non-compliance, and an inability to maintain therapeutic drug levels over the multi-week inflammatory resolution period. Here we report the development and characterization of alkaline phosphatase (ALP)-responsive enzyme-instructed self-assembling (EISA) peptide hydrogels based on the ultrashort amphiphilic sequence NapFFKY(p)-OH, covalently conjugated with dexamethasone (DEX) via an ester-cleavable succinyl linker, in both L- and D-enantiomeric forms, as injectable platforms for subconjunctival drug delivery. Both conjugates, L-NapFFK(DEX)Y(p)-OH and D-NapFFK(DEX)Y(p)-OH, were synthesized with chemical purity (87.3% and 89.8%, respectively) and theoretical DEX loading of 29.58% w/w. ALP-triggered gelation was confirmed for both enantiomeric gels at 2% w/v, with rheological characterization of the platform establishing a storage modulus plateau of approximately 294 Pa, a G'/G″ ratio of ~10:1, and gel failure at approximately 578% shear strain. Transmission electron microscopy revealed stereochemistry-dependent differences in nanofiber network architecture, with the D-enantiomer forming a comparatively looser, more porous fibrillar matrix than its L-counterpart. In vitro DEX release over 28 days demonstrated that covalent conjugation eliminates the burst release associated with physical drug entrapment (41.1% for the L physical mixture versus 14.2% and 8.3% for L- and D-conjugated systems, respectively, at 2% w/v), while D-amino acid stereochemistry provides an additional level of sustained release restraint. Proteinase K stability studies confirmed the exceptional proteolytic resistance of the D-enantiomer, retaining 92.6 ± 2.2% of intact peptide at 6 h compared with 25.3 ± 0.8% for the L-enantiomer. Ex vivo scleral permeation studies demonstrated a trend towards greater cumulative DEX permeation (10.6 vs. 6.7 µg) and tissue retention (5.6 vs. 3.2 µg) for the D vs. L-formulation over 24 h. Both formulations exhibited injection forces within acceptable limits for a 30-gauge needle for ophthalmic administration, with the D-enantiomer requiring lower force than its L-counterpart. Cell viability of Dex-conjugated peptide sequence demonstrated non toxic in ARPE-19 human retinal pigment epithelial cells across all conditions tested, confirming biocompatibility. These findings establish the backbone stereochemistry independently controls network mechanics, proteolytic stability, and drug release rate in ALP-responsive EISA hydrogels. Cumulative release over 28 days remains below that required to cover a 4-6-week postoperative course, and this work is therefore presented as a mechanistic proof-of-concept defining design principles for the platform rather than a clinically optimized formulation. Drug loading, peptide sequence, and linker chemistry are identified as the levers through which release rate may be matched to intended clinical interval.

Background/Objectives: This study examined whether dexamethasone (Dex) and decanoic acid (DA) exert complementary effects on inflammatory signaling, catabolic gene expression, and peroxisome proliferator-activated receptor gamma (PPARγ) activation in human chondrocytes. Methods: Two donor-specific primary human chondrocyte models, each derived from a single knee donor, were used, in which cells were treated with Dex (≤0.1 µM), DA (≤500 µM), or combinations thereof. Acute Interleukin-1β(IL-1β)-induced PGE2 release was evaluated in normal donor cells, whereas prolonged transcriptional responses and PPARγ DNA-binding activity were evaluated in OA donor cells. IL-1β-induced prostaglandin E2 (PGE2) release was measured by competitive ELISA after 24 h. Glyceraldehyde-3-phosphate dehydrogenase-normalized transcription of Collagen type II alpha 1, Collagen type I alpha 1, Aggrecan, SRY-Box Transcription Factor 9, Runt-Related Transcription Factor 2, and Matrix Metalloproteinase 13 (MMP13) was assessed by qRT-PCR at 7, 10-14, and 20-28 days. In addition, PPARγ DNA-binding activity was measured after 1 week. Interactions were evaluated by Loewe additivity and highest single agent (HSA) analyses. Results: Dex and DA each reduced PGE2 release, whereas co-treatment increased potency and maximal inhibition, with a Loewe combination index of 0.4 at 1 nM Dex plus 19 µM DA. In the temporal analysis, Dex plus DA showed a positive MMP13 ΔCt difference versus Dex at 10-14 days (2.42 ± 2.14; p = 0.065) and a more consistent difference at 20-28 days (1.11 ± 0.25; p = 0.016). This agreed with fixed-dose HSA findings at 14 and 28 days (ΔHSA ≈ -75 for 0.1 µM Dex plus 100 µM DA versus Dex). Co-treatment was also associated with increased PPARγ activation beyond the HSA reference (ΔHSA ≈ 0.09 for 0.1 µM Dex plus 100-250 µM DA versus Dex). Conclusions: Dex plus DA co-treatment produced complementary effects on acute PGE2 inhibition, as well as late-onset MMP13 suppression and PPARγ activity in the donor-specific chondrocyte models studied. These hypothesis-generating findings provide an in vitro rationale for future evaluation of this combination as a corticosteroid-sparing strategy.

Background: Portulaca oleracea L. (POL) has anti-inflammatory and immunomodulatory activities, but its mechanism against atopic dermatitis (AD) remains incompletely understood. Methods: 2,4-dinitrofluorobenzene (DNFB)-induced AD mice were treated orally with POL or dexamethasone for 14 days. We evaluated skin lesions, scratchizng, serum IgE, histopathology, inflammatory cytokines, skin-barrier genes, JAK/STAT phosphorylation, and fecal metabolites. Results: POL alleviated skin lesions and pruritus, reduced serum IgE concentrations, attenuated epidermal hyperplasia and inflammatory-cell and mast-cell infiltration, and restored keratinocyte architecture. It decreased IL-4, IL-13, and IL-31 expression, increased filaggrin and loricrin expression, and inhibited JAK1, STAT1, and STAT3 phosphorylation. Untargeted metabolomics showed that POL mainly regulated unsaturated fatty acid and steroid hormone biosynthesis and restored levels of anti-inflammatory and antiallergic metabolites, including (±)18-HEPE, docosahexaenoyl ethanolamide, and dehydroepiandrosterone. Conclusions: These findings indicate that POL ameliorates AD by suppressing Th2 inflammation through JAK1/STAT3 signaling, correcting lipid-metabolic disturbances, and restoring skin barrier integrity.

Background/Objectives: α-Phellandrene (α-PHEL) is a monoterpene found in essential oils and is known for its antinociceptive and anti-inflammatory properties. This study investigated the antinociceptive effects of free α-PHEL and β-cyclodextrin-associated α-PHEL (α-PHEL/β-CD) in a Complete Freund's adjuvant (CFA)-induced model of chronic inflammatory pain. Methods: Mechanical allodynia and hyperalgesia were evaluated in female Wistar rats using the von Frey and Randall-Selitto tests, respectively. Locomotor activity and motor performance were evaluated in male Swiss mice. Animals received α-PHEL (6.25-100 mg/kg) and α-PHEL/β-CD (3.12-12.5 mg/kg), as well as vehicle (2% Tween 80/0.9% saline) and dexamethasone (0.5 mg/kg, p.o.), with evaluations conducted in the von Frey test at intervals of 1 to 24 h. The antihyperalgesic effect was evaluated using α-PHEL, α-PHEL/β-CD, vehicle, and diclofenac (5 mg/kg, p.o.), with assessments in the Randall-Selitto test from 1 to 6 h. Over 10 days, the animals were treated and evaluated daily to determine the effect during repeated treatment. The involvement of the opioid pathway was assessed using naloxone, whereas the serotonergic pathway was investigated using PCPA and ketanserin in the von Frey test. Motor coordination was tested in the rotarod, and exploratory behavior was assessed in the open field. Results: α-PHEL reduced CFA-induced hyperalgesia and allodynia in both acute and chronic phases. The α-PHEL/β-CD preparation produced significant antinociceptive effects at all tested doses during repeated administration. Naloxone and 5-HT2A receptor blockade reduced the antinociceptive effect of α-PHEL, while α-PHEL and the α-PHEL/β-CD preparation did not alter locomotor activity or motor coordination. Conclusions: The α-PHEL/β-CD preparation exhibits antinociceptive activity in inflammatory pain without affecting locomotor activity or motor coordination. The findings with free α-PHEL suggest the possible contribution of opioid and serotonergic pathways to its antinociceptive effect.

Skeletal muscle aging is characterized by impaired myogenic differentiation, mitochondrial dysfunction, oxidative stress, and circadian rhythm disruption, contributing to sarcopenia and muscle atrophy. Hesperetin, a natural flavonoid, has antioxidant and mitochondrial protective effects; however, its role in skeletal muscle circadian regulation during aging remains unclear. This study investigated the effects of hesperetin (20 µM or 100 mg/kg b.w.) using D-galactose (D-gal, 20 g/L)-induced senescent C2C12 myotubes, a D-gal (150 mg/kg b.w., i.p.)-induced aging mouse model, and a dexamethasone (Dex, 20 mg/kg b.w., i.p.)-induced muscle atrophy model. In D-gal-treated mice, hesperetin improved hanging test performance and increased SDH-positive area, particularly during the active phase. Hesperetin also partially modulated core clock gene expression and mitochondrial function-related gene expression. In D-gal-induced senescent C2C12 myotubes, hesperetin improved myotube formation, reduced SA-β-gal-positive cells, DCF-DA fluorescence, and MDA levels, enhanced antioxidant enzyme activities, and improved mitochondrial-associated functional indicators, including ATP levels, mitochondrial membrane potential-related fluorescence, pMitoTimer-based mitochondrial oxidation-associated signals, and Ppargc1a expression patterns. These findings suggest that hesperetin may protect against experimentally induced skeletal muscle dysfunction by modulating time-dependent gene expression, mitochondrial-related activities, and muscle-related functional markers.