ABSTRACT Monitoring chemotherapeutic drug concentrations directly at the tumor site remains a critical unmet need in oncology, as conventional pharmacokinetic assessments based on systemic circulation fail to capture the spatial and temporal heterogeneity of drug distribution within solid tumors. Here, we report a bioresorbable, multiparametric optical sensor designed for the in situ detection of the chemotherapeutic agent doxorubicin. The sensor integrates a nanostructured porous silica scaffold with a molecularly imprinted polymer (MIP) synthetic receptor that provides shape‐ and chemistry‐selective recognition of doxorubicin molecules. Molecular binding events are transduced through two orthogonal optical signals: i) shifts in effective optical thickness and ii) fluorescence intensity changes, enabling accurate and self‐validating quantification across clinically relevant concentration ranges. The sensor operates reliably in serum with a limit of detection as low as 0.1 µg/mL, and exhibits reversible performance with minimal signal drift (<15.3%) over 12 weeks —consistent with standard chemotherapy regimens. In vivo implantation studies in mice confirm biodegradation and biocompatibility, with no evidence of local or systemic toxicity. This platform introduces a versatile strategy for multiparametric, bioresorbable chemical sensing using MIP synthetic receptors, establishing a foundation for future implantable diagnostics in precision chemotherapy.

Developing bioresorbable energy sources that eliminate the need for secondary surgery for device removal remains a major challenge in resorbtronics. In this work, we present an alternative fabrication strategy for new bioresorbable quasi-solid Na-ion batteries using Mo or Mg thin films as current collectors. The assembled batteries were characterized using scanning electron microscopy, spectroscopic techniques including X-ray photoelectron spectroscopy, physicochemical, and electrochemical characterization techniques. Results demonstrate that the choice of current collector strongly influences electrochemical performance. Mo-based batteries delivered a discharge capacity of 6.8 mAh cm- 2 at a C/2 rate, approximately twice that of Mg-based counterparts whose performance is limited by oxidation reactions. Moreover, Mo-based batteries exhibited stable cycling with 86% capacity retention after 100 cycles at 2C. In vitro cytotoxicity assays showed cell viability above the 70% threshold indicating that the tested materials are non-cytotoxic according to ISO 10993 guidelines. Implantation studies confirmed safe degradation of Mo-based batteries supported by in vivo monitoring of animal health behavior and ex vivo organ analyses, including organ weight, ALT measurements, and histological evaluation of skin at the implantation site after three months. Additionally, the operational lifetime of implanted batteries can be tuned from days to months by controlling encapsulation layer thickness.

Background/Objectives MC4R expression and its role in colorectal and anaplastic thyroid cancers, where resistance to therapy and lack of standard treatments remain significant challenges, are poorly understood. This study aimed to investigate MC4R as a potential therapeutic target in these cancers using the selective antagonist ML00253764 (ML), alone and in combination with vinorelbine (VNR) and irinotecan (or its active metabolite SN-38). Methods: Human colorectal adenocarcinoma HT-29, Caco-2, and anaplastic thyroid carcinoma 8305C cell lines were used. MC4R expression was assessed by Real-Time PCR with validated primers (Assay ID Hs00271877_s1), immunofluorescence, and Western blotting. Proliferation and apoptosis assays were conducted with ML, and synergy with VNR and SN-38 was evaluated by Combination Index and Loewe methods. ERK1/2 phosphorylation was measured using an ELISA assay. In vivo studies were conducted by injecting tumor cells into Athymic Nude-Foxn1nu mice, treated with ML, VNR, irinotecan, or their combinations. Results: MC4R expression was confirmed in all cell lines. ML treatment inhibited MC4R, producing antiproliferative and pro-apoptotic effects, with IC50 values of 7667 ± 2144.6 nM (8305C), 806.4 ± 321.8 nM (HT-29), and 2993 ± 1135.2 nM (Caco-2). In combination with VNR and SN-38, ML exhibited significant synergy in vitro and reduced tumor volume in vivo without causing weight loss or adverse effects in mice. Conclusions This study identifies ML as a promising therapeutic agent that, when combined with chemotherapy, may offer a novel strategy for treating colorectal and anaplastic thyroid cancers.

Cancer treatment, particularly chemotherapy, requires balancing efficacy and toxicity. Although traditional monitoring methods can lead to suboptimal outcomes, emerging implantable chemical sensors can complement them by providing precise, real-time drug monitoring at tumor sites, although the technology remains in its early stages. Here, we introduce an ultrathin, bioresorbable implantable biosensor for real-time doxorubicin monitoring in vivo with high spatiotemporal resolution. The sensor amplifies the drug's fluorescence, enabling successful tracking of doxorubicin through the skin in live mice following intravenous injection. When paired with a reusable electronic patch, the biosensor facilitates seamless data collection and wireless transmission. A 3-month biocompatibility study, including systemic toxicity assessments, histological and blood analyses, confirms complete biodegradation with no observed toxicity. By directly measuring chemotherapeutic drug levels in tissues over time, our sensor enhances traditional monitoring methods, enabling clinicians to optimize dosing during cancer treatment and reduce the risk of locoregional recurrence following tumor removal.

In this work, an alternative fabrication process is implemented to fabricate a bioresorbable Na-ion battery showing excellent electrochemical performance (discharge capacity of 5.1 mAh cm-2) and no toxicity after being disintegrated under in vivo conditions. Solely composed of biocompatible materials, the proposed all-solid-state rechargeable battery implanted under the skin is capable of disintegrating safely. The operating days and lifetime of this novel energy storage system are evidenced that after being implanted in artificial skin can be finely controlled by tuning the thickness of the encapsulation layer, rendering possible the design of "on-demand" bio-eliminable batteries that may operate days or several weeks. The toxicity tests and the lack of organ damage performed by ex vivo analyses after 3 months confirmed the safety of the approach. In addition, wireless recharge of the battery is demonstrated through the skin using an inductive charger to establish the proof-of-concept. Preliminary tests revealed that wireless recharge of the subcutaneous implanted battery is achieved in 30 min, and that recharge remains possible in 1 h for deeper implanted batteries. The high versatility of the concept is definitely appealing to address the various needs of the temporary medical device market.

Introduction: Histamine administered intracerebroventricularly (icv) induces a resuscitating effect in hemorrhage-shocked rats. Dopamine receptors are present in neuronal pathways involved in central cardiovascular regulation; therefore, the aim of the study was to examine the effects of pre-treatment with dopamine receptor antagonists on histamine-induced cardiovascular effects in hemorrhagic shock. Material and methods: Male Wistar rats subjected to a reversible hemorrhagic hypotension with mean arterial pressure (MAP) of 30–35 mmHg were anaesthetized with ketamine/xylazine (100 mg/kg + 10 mg/kg, intraperitoneally). Immediately after bleeding terminated, the animals were pre-treated icv with dopamine receptor antagonists or saline; 5 min later they were treated icv with histamine (50 nmol) or saline. Results: Hemorrhagic hypotension was accompanied by decreases in pulse pressure (PP), heart rate (HR), and mesenteric blood flow (MBF). Histamine induced increases in MAP, HR, and MBF, with a decrease in PP as compared to the control group. Pre-treatment with the dopamine D4 receptor antagonist L-745,870 potentiated histamine-induced MAP and MBF changes, with no influence on PP or HR. There were neither the influence of the other dopamine receptor antagonists on histamine-mediated action nor the effects of dopamine receptor antagonists given alone in the control groups. Conclusions: Dopamine, acting via D4 receptors, is able to modulate the central histamine-induced pressor effect in hemorrhage-shocked rats.

Light is a crucial tool in medicine for diagnosis and treatment. New light sources called organic light-emitting devices (OLEDs) have been integrated with various extracorporeal and implantable devices to sense or stimulate specific cellular responses. However, one of the current challenges remaining is to design a transient OLED that functions effectively and completely dissolves inside the human body when it is no longer needed, without affecting homeostasis. This work addresses this issue by creating the first transient chitosan-based OLED. The OLED is turned on at low voltages and emits a bright green light with a maximum luminance of 36 cd/m2. In vitro assays showed that all layers break down under physiological settings, and the biocompatibility was confirmed by in vivo tests. The chitosan-based OLED represents a breakthrough in transient electronics and advances implantable light-based biomedical applications.

The aim of our study is to investigate in vitro and in vivo MC4R as a novel target in melanoma using the selective antagonist ML00253764 (ML) alone and in combination with vemurafenib, a B-rafV600E inhibitor. The human melanoma B-raf mutated A-2058 and WM 266-4 cell lines were used. An MC4R null A-2058 cell line was generated using a CRISPR/Cas9 system. MC4R protein expression was analysed by western blotting, immunohistochemistry, and immunofluorescence. Proliferation and apoptotic assays were performed with ML00253764, whereas the synergism with vemurafenib was evaluated by the combination index (CI) and Loewe methods. ERK1/2 phosphorylation and BCL-XL expression were quantified by western blot. In vivo experiments were performed in Athymic Nude-Foxn1nu male mice, injecting subcutaneously melanoma cells, and treating animals with ML, vemurafenib and their concomitant combination. Comet and cytome assays were performed. Our results show that human melanoma cell lines A-2058 and WM 266-4, and melanoma human tissue, express functional MC4R receptors on their surface. MC4R receptors on melanoma cells can be inhibited by the selective antagonist ML, causing antiproliferative and proapoptotic activity through the inhibition of phosphorylation of ERK1/2 and a reduction of BCL-XL. The concomitant combination of vemurafenib and ML caused a synergistic effect on melanoma cells in vitro and inhibited in vivo tumor growth in a preclinical model, without causing mouse weight loss or genotoxicity. Our original research contributes to the landscape of pharmacological treatments for melanoma, providing MC4R antagonists as drugs that can be added to established therapies.

Background: Increasing evidence highlights the importance of novel players in Alzheimer's disease (AD) pathophysiology, including alterations of lipid metabolism and neuroinflammation. Indeed, a potential involvement of Proprotein convertase subtilisin/kexin type 9 (PCSK9) in AD has been recently postulated. Here, we first investigated the effects of PCSK9 on neuroinflammation in vitro. Then, we examined the impact of a genetic ablation of PCSK9 on cognitive performance in a severe mouse model of AD. Finally, in the same animals we evaluated the effect of PCSK9 loss on A beta pathology, neuroinflammation, and brain lipids.Methods: For in vitro studies, U373 human astrocytoma cells were treated with A beta fibrils and human recombinant PCSK9. mRNA expression of the proinflammatory cytokines and inflammasome-related genes were evaluated by q-PCR, while MCP-1 secretion was measured by ELISA. For in vivo studies, the cognitive performance of a newly generated mouse line -obtained by crossing 5XFADHet with PCSK9KO mice - was tested by the Morris water maze test. After sacrifice, immunohistochemical analyses were performed to evaluate A beta plaque deposition, distribution and composition, BACE1 immunoreactivity, as well as microglia and astrocyte reactivity. Cholesterol and hydroxysterols levels in mouse brains were quantified by fluorometric and LC-MS/MS analyses, respectively. Statistical comparisons were performed according to one-or two-way ANOVA, two-way repeated measure ANOVA or Chi-square test.Results: In vitro, PCSK9 significantly increased IL6, IL1B and TNFA mRNA levels in A beta fibrils-treated U373 cells, without influencing inflammasome gene expression, except for an increase in NLRC4 mRNA levels. In vivo, PCSK9 ablation in 5XFAD mice significantly improved the performance at the Morris water maze test; these changes were accompanied by a reduced corticohippocampal A beta burden without affecting plaque spatial/ regional distribution and composition or global BACE1 expression. Furthermore, PCSK9 loss in 5XFAD mice induced decreased microgliosis and astrocyte reactivity in several brain regions. Conversely, knocking out PCSK9 had minimal impact on brain cholesterol and hydroxysterol levels. Conclusions: In vitro studies showed a pro-inflammatory effect of PCSK9. Consistently, in vivo data indicated a protective role of PCSK9 ablation against cognitive impairments, associated with improved A beta pathology and attenuated neuroinflammation in a severe mouse model of AD. PCSK9 may thus be considered a novel pharmacological target for the treatment of AD.

Among the strategies to overcome the underperformance of statins in cardiovascular diseases (CVDs), the development of drugs targeting the Proprotein Convertase Subtilisin-like Kexin type 9 (PCSK9) is considered one of the most promising. However, only anti-PCSK9 biological drugs have been approved to date, and orally available small-molecules for the treatment of hypercholesterolemic conditions are still missing on the market. In the present work, we describe the application of a phenotypic approach to the identification and optimization of 4-amino-2-pyridone derivatives as a new chemotype with anti-PCSK9 activity. Starting from an in-house collection of compounds, functional assays on HepG2 cells followed by a chemistry-driven hit optimization campaign, led to the potent anti-PCSK9 candidate 5c. This compound, at 5 μM, totally blocked PCSK9 secretion from HepG2 cells, significantly increased LDL receptor (LDLR) expression, and acted cooperatively with simvastatin by reducing its induction of PCSK9 expression. Finally, compound 5c also proved to be well tolerated in C57BL/6J mice at the tested concentration (40 mg/kg) with no sign of toxicity or behavior modifications.

IntroductionAlzheimer’s disease (AD) is the most frequent cause of dementia and still lacks effective therapy. Clinical signs of AD include low levels of endogenous melanocortins (MCs) and previous studies have shown that treatment with MC analogs induces neuroprotection in the early stages of AD. MethodsWe investigated the neuroprotective role of MCs in two transgenic mouse models of severe AD using 5 and 7 month-old (mo) 5XFAD mice and 9 and 12 mo 3xTg mice. These mice were subjected to a chronic stimulation of MC receptors (MCRs) with MC analogue Nle4-D-Phe7-α-melanocyte stimulating hormone (NDP-α-MSH, 340 μg/kg, i.p.). Mouse behavior and ex-vivo histological and biochemical analyses were performed after 50 days of treatment.ResultsOur analysis demonstrated an improvement in cognitive abilities of AD mice at late stage of AD progression. We also showed that these protective effects are associated with decreased levels of hyperphosphorylated Tau but not with Aβ burden, that was unaffected in the hippocampus and in the cortex of AD mice. In addition, an age-dependent NDP effect on glial reactivity was observed only in 3xTg mice whereas a global downregulation of p38 mitogen-activated protein kinase was selectively observed in 7 mo 5XFAD and 14 mo 3xTg mice.ConclusionOur results suggest that MCR stimulation by NDP-α-MSH could represent a promising therapeutic strategy in managing cognitive decline also at late stage of AD, whereas the effects on neuroinflammation may be restricted to specific stages of AD progression.

Aim: Impairment of cholesterol homeostasis is one of the multiple etiopathological mechanisms at the origin of both cardiovascular and neurodegenerative diseases. The PCSK9 protein, known for its role in the degradation of hepatic LDLR and plasma cholesterol regulation, is expressed also in the CNS, where it exacerbates -amyloid neurotoxicity and reduces neuronal cholesterol uptake, suggesting an involvement in AD. This study proposes an in vitro screening of molecules (MR) with inhibitory activity on PCSK9, selecting the best compounds to test their activity on cerebral cell models and their in vivo tolerability. Methods: 30 newly synthesized compounds were tested at increasing concentrations on human hepatoma cells (HepG2) to evaluate their cytotoxicity and efficacy in inhibiting PCSK9. MR-3 was tested on human neuroblastoma cells (SH-SY5Y) overexpressing PCSK9 to assess neurotoxicity and cholesterol uptake. Cytotoxicity was determined through MTT assay; PCSK9 secretion was quantified with an ELISA kit; and radioisotopic techniques measured cholesterol uptake . Three compounds were selected to be tested in vivo on C57BL/6 mice at a dose of 40 mg/Kg for 7 days to evaluate: tolerability with SHIRPA test; plasma lipid profile by ELISA assay; biodistribution in plasma and brain through LC-MS/MS. Results: Among the tested compounds, MR-3, MR-532, MR-533 demonstrated no sign of cytotoxicity and the greatest efficacy on HepG2 cells (IC50=1.7μM; 5.7μM; 6.1μM). Neuronal cholesterol uptake was restored after treatment with MR-3 at 10μM (p<0,05). MR-3, MR-532, and MR-533 exhibited good in vivo tolerability; MR-3 and MR-532 were detected in plasma and brain tissue. Conclusions: Preliminary in vitro screening allowed the identification of MR-3, MR-532, MR-533 as promising PCSK9 inhibitors. The outcome of MR-3 on neuronal cholesterol uptake may suggest a neuroprotective effect to be further investigated. In vivo treatment with selected inhibitors shown absence of toxicity, however, it is necessary to bring proof of efficacy.

Here, the authors report on the manufacturing and in vivo assessment of a bioresorbable nanostructured pH sensor. The sensor consists of a micrometer-thick porous silica membrane conformably coated layer-by-layer with a nanometer-thick multilayer stack of two polyelectrolytes labeled with a pH-insensitive fluorophore. The sensor fluorescence changes linearly with the pH value in the range 4 to 7.5 upon swelling/shrinking of the polymer multilayer and enables performing real-time measurements of the pH level with high stability, reproducibility, and accuracy, over 100 h of continuous operation. In vivo studies carried out implanting the sensor in the subcutis on the back of mice confirm real-time monitoring of the local pH level through skin. Full degradation of the pH sensor occurs in one week from implant in the animal model, and its biocompatibility after 2 months is confirmed by histological and fluorescence analyses. The proposed approach can be extended to the detection of other (bio)markers in vivo by engineering the functionality of one (at least) of the polyelectrolytes with suitable receptors, thus paving the way to implantable bioresorbable chemical sensors.

Background and Aims: PCSK9 may be involved in Alzheimer's disease (AD), although the underlying mechanisms are not fully clarified. This study aims to investigate PCSK9' influence on brain cholesterol transport, essential to maintain neuronal functions, and neuroinflammation.Methods: Human astrocytoma U373 cells exposed to exogenous PCSK9 and human neuroblastoma SH-SY5Y cells overexpressing PCSK9 have been used. The incubation with Amyloid β (Aβ) fibrils was used to reproduce AD-like conditions. Cholesterol synthesis, efflux and uptake were evaluated by radioisotopic assays, cholesterol content by a fluorometric assay, gene and protein expression through qRT-PCR and Western Blot (WB).Results: In U373 PCSK9 increased cholesterol biosynthesis (p<0.05) and reduced LDLR and apoER2 expression (p<0.05). PCSK9 reduced intracellular cholesterol content (p<0.05), with a strengthened effect when co-incubated with Aβ (p<0.01). PCSK9 didn't alter ABCA1- and ABCG1-mediated cholesterol efflux. Conversely, ABCA1-efflux and expression were reduced by Aβ (p<0.001). In PCSK9-overexpressing SH-SY5Y cells, apoE-HDL uptake was reduced (p<0.001) compared to control cells, independently of Aβ. PCSK9 overexpression reduced LDLR and ApoER2 expression (p<0.05). Cholesterol biosynthesis was reduced in PCSK9 overexpressing SH-SY5Y compared to controls (p<0.01), independently of Aβ. The overexpression of PCSK9 in SH-SY5Y furtherly increased the neurotoxicity induced by Aβ (p<0.05). In U373 PCSK9 enhanced the neuroinflammation induced by Aβ, increasing IL-6, IL-1β, TNF-α (p<0.05), and inflammasome Pyrin and NLRC4 gene expression although not statistically significant, with a minimal degrading effect on CD36 expression.Conclusions: PCSK9, cooperating with Aβ, impairs brain cholesterol transport and worsened neuroinflammation, with negative consequences on neuronal survival. Hence, PCSK9 may be considered a pathogenic factor in AD. Background and Aims: PCSK9 may be involved in Alzheimer's disease (AD), although the underlying mechanisms are not fully clarified. This study aims to investigate PCSK9' influence on brain cholesterol transport, essential to maintain neuronal functions, and neuroinflammation. Methods: Human astrocytoma U373 cells exposed to exogenous PCSK9 and human neuroblastoma SH-SY5Y cells overexpressing PCSK9 have been used. The incubation with Amyloid β (Aβ) fibrils was used to reproduce AD-like conditions. Cholesterol synthesis, efflux and uptake were evaluated by radioisotopic assays, cholesterol content by a fluorometric assay, gene and protein expression through qRT-PCR and Western Blot (WB). Results: In U373 PCSK9 increased cholesterol biosynthesis (p<0.05) and reduced LDLR and apoER2 expression (p<0.05). PCSK9 reduced intracellular cholesterol content (p<0.05), with a strengthened effect when co-incubated with Aβ (p<0.01). PCSK9 didn't alter ABCA1- and ABCG1-mediated cholesterol efflux. Conversely, ABCA1-efflux and expression were reduced by Aβ (p<0.001). In PCSK9-overexpressing SH-SY5Y cells, apoE-HDL uptake was reduced (p<0.001) compared to control cells, independently of Aβ. PCSK9 overexpression reduced LDLR and ApoER2 expression (p<0.05). Cholesterol biosynthesis was reduced in PCSK9 overexpressing SH-SY5Y compared to controls (p<0.01), independently of Aβ. The overexpression of PCSK9 in SH-SY5Y furtherly increased the neurotoxicity induced by Aβ (p<0.05). In U373 PCSK9 enhanced the neuroinflammation induced by Aβ, increasing IL-6, IL-1β, TNF-α (p<0.05), and inflammasome Pyrin and NLRC4 gene expression although not statistically significant, with a minimal degrading effect on CD36 expression. Conclusions: PCSK9, cooperating with Aβ, impairs brain cholesterol transport and worsened neuroinflammation, with negative consequences on neuronal survival. Hence, PCSK9 may be considered a pathogenic factor in AD.

Here we report on a bioresorbable fluorescence sensor for in vivo pH monitoring. The sensor leverages a nanometer-thick multilayer stack of polyelectrolytes labelled with a pH-insensitive fluorophore conformably deposited within a porous silica membrane—thickness of a few micrometers—to increase fluorescence intensity up to 600 times and enable reliable measurements through skin.

The Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) involvement in Alzheimer’s disease (AD) is poorly investigated. We evaluated the in vitro PCSK9 modulation of astrocyte cholesterol metabolism and neuronal cholesterol supplying, which is fundamental for neuronal functions. Moreover, we investigated PCSK9 neurotoxic effects. In human astrocytoma cells, PCSK9 reduced cholesterol content (−20%; p < 0.05), with a greater effect in presence of beta amyloid peptide (Aβ) (−37%; p < 0.01). PCSK9 increased cholesterol synthesis and reduced the uptake of apoE-HDL-derived cholesterol (−36%; p < 0.0001), as well as the LDL receptor (LDLR) and the apoE receptor 2 (ApoER2) expression (−66% and −31%, respectively; p < 0.01). PCSK9 did not modulate ABCA1- and ABCG1-cholesterol efflux, ABCA1 levels, or membrane cholesterol. Conversely, ABCA1 expression and activity, as well as membrane cholesterol, were reduced by Aβ (p < 0.05). In human neuronal cells, PCSK9 reduced apoE-HDL-derived cholesterol uptake (−41%; p < 0.001) and LDLR/apoER2 expression (p < 0.05). Reduced cholesterol internalization occurred also in PCSK9-overexpressing neurons exposed to an astrocyte-conditioned medium (−39%; p < 0.001). PCSK9 reduced neuronal cholesterol content overall (−29%; p < 0.05) and increased the Aβ-induced neurotoxicity (p < 0.0001). Our data revealed an interfering effect of PCSK9, in cooperation with Aβ, on brain cholesterol metabolism leading to neuronal cholesterol reduction, a potentially deleterious effect. PCSK9 also exerted a neurotoxic effect, and thus represents a potential pharmacological target in AD.

Background and Aims: The Proprotein convertase subtilisin/kexin type 9 (PCSK9) seems to be involved in Alzheimer's disease (AD) pathogenesis, although the mechanisms are still unknown. We investigated PCSK9 influence on cerebral lipid metabolism and neuroinflammation in human cell models of astrocytes and neurons.