Chronic wounds (CWs) are characterized by persistent inflammation and bacterial biofilms, which hinder healing and contribute to antibiotic resistance. Therefore, innovative treatments with both anti-inflammatory and antibiofilm properties are urgently needed. Here, cobalt phthalocyanine (CoPc), a photo-excitable dye, is combined with polyphenolic lignin to develop CoPc-Lig nanoparticles (NPs). These NPs demonstrate antioxidant activity by scavenging reactive oxygen species and inhibiting key enzymes implicated in CW pathophysiology. Moreover, they are internalized into Staphylococcus aureus and Pseudomonas aeruginosa biofilms, a critical feature for enhancing antibacterial effects. Upon near-infrared light excitation, CoPc-Lig NPs produce a thermal increase, which reduces bacterial viability and disrupts biofilm integrity. This mild photothermal effect is particularly advantageous in CW treatment, as excessive temperatures can damage newly formed tissue. Additionally, the NPs exhibit strong photoacoustic (PA) properties, enabling their use in PA imaging, an emerging non-invasive technique for real-time monitoring. The PA signal remains stable over time and is detected in ex vivo tissue phantoms. These findings highlight the potential of CoPc-Lig NPs as a theragnostic platform for CW management, integrating antimicrobial cobalt, antioxidant polyphenols, and photo-excitable phthalocyanines. Future studies will focus on optimizing photothermal treatment conditions and exploring synergies with debridement and antibacterial agents to enhance therapeutic outcomes.

Polydopamine nanoparticles (PDNPs) are a class of nanomaterials formed by the self-polymerization of dopamine. They exhibit high biocompatibility, biodegradability, antioxidant properties, and ease of functionalization and can serve as photothermal agents when exposed to near-infrared (NIR) light. Another notable feature of PDNPs is their potential to act as contrast agents in photoacoustic imaging (PAI). In this technique, light absorption by endogenous chromophores or nanostructures induces thermal expansion, which generates sound waves that can be exploited to create images. Although PDNPs have shown promise as PAI contrast agents, their capabilities remain underexplored and insufficiently characterized in biological systems. This study presents the first comprehensive evaluation of PDNPs as PAI contrast agents. We investigated PDNPs of various sizes (∼150-1000 nm) and assessed their photoacoustic performance in diverse environments, including aqueous dispersions, ex vivo tissues, U87 cancer cell spheroids, fertilized quail eggs, and zebrafish embryos. Additionally, experimental results supported the development of a computational model to predict PDNP photoacoustic properties. Overall, this work highlights the significant, yet largely unexplored, potential of PDNPs as label-free PAI contrast agents, contributing to their future exploitation in clinical imaging.

Background Sotagliflozin, a potent dual inhibitor of sodium-glucose co-transporters 1 and 2 (SGLT1/2), is the first FDA-approved SGLT inhibitor for the comprehensive management of heart failure. To elucidate its systemic pharmacokinetics and target engagement, we developed [ 11 C]sotagliflozin, the carbon-11 labeled isotopologue able to serve as a direct translational tool to map the in vivo biodistribution and molecular interactions of the parent drug using positron emission tomography/computed tomography (PET/CT). Results [ 11 C]sotagliflozin was efficiently synthesized via 11 C-methylation, yielding a decay-corrected radiochemical yield (RCY) of (66 ± 5)% within 30 minutes. The tracer exhibited high radiochemical purity (RCP) (99 ± 1)% and molar activity (MA) of 62 ± 5 GBq/µmol. HPLC analysis confirmed its robust in vitro stability in both saline and plasma for up to 120 minutes. Dynamic microPET/CT imaging in mice demonstrated high-contrast tracer accumulation in the renal cortex, liver, and gastrointestinal tract, reflecting the primary expression sites of SGLT1/2. Radio-metabolite profiling confirmed the presence of parent compound in the target organs alongside other metabolites derived from glucuronidation or oxidation reactions. Conclusion The radiosynthesis of [ 11 C]sotagliflozin is efficient, yielding high RCY, RCP, and moderate MA. The tracer exhibits excellent in vitro stability in both saline and plasma. In vivo evaluation confirmed a biodistribution profile consistent with the dual-inhibition mechanism, validating [ 11 C]sotagliflozin as a promising tool for the noninvasive assessment of SGLT1/2 pharmacology.

In this study, hierarchical melanin-like nanoparticles with mimosa-like shape (HMNs) are produced by initiating dopamine polymerization on the surface of wrinkled silica nanoparticles (WSNs), followed by the removal of the ceramic template in acidic environment. The nanostructures are further functionalized with (poly)ethylene glycol (PEG) and decorated with either Fe(III) or Ag(I) cations. The engineered nanoparticles exhibit significant nanozyme activities, mimicking the catalytic functions of catalase (CAT), superoxide dismutase (SOD) and peroxidase endogenous enzymes. The Fe(III)-loaded nanoparticles demonstrate notable photothermal performance, achieving an increase of 20 degrees C upon continuous near infrared (NIR) laser irradiation. Furthermore, Fe(III) chelation results in a transverse relaxation effect (R2 = 10.6 s- 1mM- 1) making them effective T2-weighted magnetic resonance imaging (MRI) contrast agents. The incorporation of Ag(I) cations leads to the formation of nanometric silver clusters at the nanoparticle surface, enhancing the photoacoustic signal through the localized surface plasmon resonance (SPR) effect under pulsed near NIR laser excitation. They result biocompatible in Human Umbilical Vein Endothelial Cells (HUVEC) cells and able to load with good efficiency a peptidomimetic of suppressor of cytokine signaling (SOCS1) endowed with anti-inflammatory effects. These engineered nanostructures candidate to be safe and versatile theragnostic platforms for drug delivery, photoacoustic imaging, photothermal therapy and MRI.

Radiotherapy remains a cornerstone in metastatic cancer treatment but is often hindered by tumor hypoxia and radioresistance. Gold nanorods (AuNRs) offer promise in enhancing radiotherapy through hyperthermia, yet their clinical impact is limited by poor tumor targeting. Building on the previous findings demonstrating the tumor-homing ability of Endothelial Colony Forming Cells (ECFCs) loaded with AuNRs, this study advances their use as a biologically targeted delivery system for precise radiotherapy enhancement. Using 3D in vitro tumor models and in vivo studies with nude rats, it is demonstrated that ECFCs actively home to hypoxic tumor regions, overcoming traditional nanoparticle delivery limitations. This targeted approach ensures efficient AuNR accumulation, enhancing photothermal activation and maximizing radiosensitization. In vitro, ECFC-loaded AuNRs significantly amplify radiotherapy effects, inducing ferroptosis in melanoma and inhibiting autophagy in breast cancer cells-revealing distinct tumor-specific mechanisms. Moreover, ECFC-AuNRs suppress tumor proliferation and angiogenesis, blocking vessel-like structure formation in vitro and in vivo. By integrating cellular therapy with nanotechnology, this study presents a novel strategy to counter radioresistance and improve therapeutic precision. These findings lay the foundation for a clinically viable, patient-specific approach, unlocking new possibilities in advanced cancer treatment.

The combination of photoacoustic imaging (PAI) and photothermal therapy (PTT) is an attractive approach in cancer management due to the non-invasive features combined with real-time imaging and selective tissue damage by non-ionizing radiation. This approach is especially appealing for Head and Neck Squamous Cell Carcinoma (HNSCC) management, where up to 40% of patients require modifications of the treatment regimen. On the other hand, most of the agents developed for PAI/PTT suffer from persistence or re-shaping issues. Here, a unique non-persistent plasmon nano-architecture (tNAs-IRDye) is presented that simultaneously acts as a contrast agent for PAI and as a photothermal transducer for PTT. The tNAs-IRDye are fully characterized and evaluated in vitro and ex vivo, and their performance as theranostic agents is assessed in HPV-negative HNSCC murine models. A significant modulation of tumor growth is obtained in vivo upon intratumoral injection of tNAs-IRDye and subsequent NIR irradiation compared to the solely irradiated control. The outcomes of this study exhibit a noteworthy potential to foster the development of innovative clinical strategies for the management of HPV-negative head and neck carcinoma. A unique class of non-persistent nano-architectures that conveniently combines photoacoustic and photothermal features are designed, produced, characterized, and explored. The nano-architectures support real-time imaging and the non-ionizing treatment of HPV-negative head/neck carcinoma providing a viable alternative for cancer management that overcomes the clinical limitations associated to the standard chemo/radio-treatments and the metal nanoparticle-based approaches. image

The development of biosafe theranostic nanoplatforms has attracted great attention due to their multifunctional behavior, reduced potential toxicity, and improved long-term safety. When considering photoacoustic contrast agents and photothermal conversion tools, melanin and constructs like melanin are highly appealing due to their ability to absorb optical energy and convert it into heat. Following a sustainable approach, in this study, silver-melanin like-silica nanoplatforms are synthesized exploiting different bio-available and inexpensive phenolic acids as potential melanogenic precursors and exploring their role in tuning the final systems architecture. The UV-Vis combined with X-Ray Diffraction investigation proves metallic silver formation, while Transmission Electron Microscopy analysis reveals that different morphologies can be obtained by properly selecting the phenolic precursors. By looking at the characterization results, a tentative formation mechanism is proposed to explain how phenolic precursors' redox behavior may affect the nanoplatforms' structure. The antibacterial activity experiments showed that all synthesized systems have a strong inhibitory effect on Escherichia coli, even at low concentrations. Furthermore, very sensitive Photoacoustic Imaging capabilities and significant photothermal behavior under laser irradiation are exhibited. Finally, a marked influence of phenol nature on the final system architecture is revealed resulting in a significant effect on both biological and photoacoustic features of the obtained systems. These melanin-based hybrid systems exhibit excellent potential as triggerable nanoplatforms for various biomedical applications.

Breast cancer is a complex and diverse disease that requires accurate diagnostic methods and customized treatment approaches to enhance patient outcomes. In this study, we investigate the potential of nylon-11 nanoparticles (nylon NPs) for both imaging and therapy of breast cancer. Nylon NPs possess excellent photoacoustic properties, which enable them to detect and locate drug delivery to the tumor with high sensitivity. This suggests that nylon NPs may be a valuable tool for improving breast cancer diagnosis and treatment. Comprehensive characterization has been performed, including morphological analysis and spectroscopic studies. Further modification with diagnostic and therapeutic agents, such as trastuzumab, sorafenib, and nutlin-3a, enhances their specificity and efficacy in targeting breast cancer cells. The drug-loaded nanoparticles exhibit controlled release profiles under various pH conditions, mimicking the tumor microenvironment. Cytocompatibility studies reveal the biocompatibility of bare nylon NPs, while drug-loaded nanoparticles show concentration-dependent cytotoxic effects, indicating their potential as therapeutic agents. Moreover, cellular internalization studies confirm the efficient uptake by breast cancer cells. Overall, this research lays the groundwork for the development of novel nanomedicine approaches aimed at addressing the challenges associated with breast cancer diagnosis and treatment, offering promising avenues for precise cancer management.

Residual nonvisible bladder cancer after proper treatment caused by technological and therapeutic limitations is responsible for tumor relapse and progression. This study aimed to demonstrate the feasibility of a solution for simultaneous detection and treatment of bladder cancer lesions smaller than one millimeter. The α5β1 integrin was identified as a specific marker in 81% of human high-grade nonmuscle invasive bladder cancers and used as a target for the delivery of targeted gold nanorods (GNRs). In a preclinical model of orthotopic bladder cancer expressing the α5β1 integrin, the photoacoustic imaging of targeted GNRs visualized lesions smaller than one millimeter, and their irradiation with continuous laser was used to induce GNR-assisted hyperthermia. Necrosis of the tumor mass, improved survival, and computational modeling were applied to demonstrate the efficacy and safety of this solution. Our study highlights the potential of the GNR-assisted theranostic strategy as a complementary solution in clinical practice to reduce the risk of nonvisible residual bladder cancer after current treatment. Further validation through clinical studies will support the findings of the present study.

Bioinspired nanoparticles have recently been gaining attention as promising multifunctional nanoplatforms for therapeutic applications in cancer, including breast cancer. Here, the efficiency of the chemo-photothermal and photoacoustic properties of hybrid albumin-modified nanoparticles (HSA-NPs) loaded with doxorubicin was evaluated in a three-dimensional breast cancer cell model. The HSA-NPs showed a higher uptake and deeper penetration into breast cancer spheroids than healthy breast cell 3D cultures. Confocal microscopy revealed that, in tumour spheroids incubated with doxorubicin-loaded NPs for 16 h, doxorubicin was mainly localised in the cytoplasm, while a strong signal was detectable at the nuclear level after 24 h, suggesting a time-dependent uptake. To evaluate the cytotoxicity of doxorubicin-loaded NPs, tumour spheroids were treated for up to 96 h with increasing concentrations of NPs, showing marked toxicity only at the highest concentration of doxorubicin. When doxorubicin administration was combined with laser photothermal irradiation, enhanced cytotoxicity was observed at lower concentrations and incubation times. Finally, the photoacoustic properties of doxorubicin-loaded NPs were evaluated in tumour spheroids, showing a detectable signal increasing with NP concentration. Overall, our data show that the combined effect of chemo-photothermal therapy results in a shorter exposure time to doxorubicin and a lower drug dose. Furthermore, owing to the photoacoustic properties of the NPs, this nanoplatform may represent a good candidate for theranostic applications.

Abstract Early detection and removal of bladder cancer (BC) is crucial to prevent tumor recurrence and progression. Various imaging modalities have been used to diagnose BC, including computed tomography urography, intravenous urography, ultrasound echography, multiparametric magnetic resonance imaging, cystoscopy, and cystoscopy in conjunction with intravesical instillation of hexaminolaevulinic acid, a photodynamic diagnostic agent. However, all these imaging techniques show a very poor detection rate of small (<5mm) and flattened cancer lesions. Because of this limitation, patients with BC frequently relapse after initial diagnosis and need frequent follow-ups and treatments, resulting in a poor quality of life. For the same reason, BC has the highest cost/patient among all cancers. We have recently developed a new methodology to detect bladder cancer lesions based on bladder instillation with GNRs@Chit-Iso4, a nanosystem consisting of gold nanorods (GNRs) decorated with chitosan and functionalized with the head-to-tail cyclized [CphgisoDGRG] peptide (Iso4, a selective ligand of alpha5beta1-integrin expressed by BC cells), followed by low-frequency ultrasound-assisted shaking of nanoparticles necessary to prevent their sedimentation, and photoacoustic imaging of targeted tumor lesions. In murine models, this procedure can detect orthotopic BC lesions <0.5 mm, undetectable by standard imaging modalities (Alchera et al., Photoacoustic, 2022). In the attempt to develop a simpler and more effective imaging modality of BC, we have produced and preclinically evaluated new GNRs decorated with lipoic acid-polyethylene glycol (PEG -5KDa) and functionalized with Iso4. The resulting product, obtained by a simple 2-step procedure and called GNRs@PEG5K-Iso4, efficiently recognized alpha5beta1- and alpha5beta1-expressing cells, was stable in 90% urine, and was resistant to freezing- or salt-induced aggregation.GNRs@PEG5K-Iso4 did not undergo sedimentation after instillation into the bladder, thereby avoiding the need of the complex ultrasound-assisted shaking of nanoparticles and could efficiently detect BC lesions smaller than <0.5 mm in murine models. These results suggest that GNRs@PEG5K-Iso4 represents a simple and robust contrast agent for photoacoustic imaging and early diagnosis of small BC lesions. Citation Format: Massimo Alfano, Elisa Alchera, Angelina Sacchi, Alessandro Gori, Irene Locatelli, Anna Maria Gasparri, Barbara Colombo, Giulia Anderluzzi, Paolo Armanetti, Luca Minichetti, Andrea Salonia, Angelo Corti, Flavio Curnis. Gold nanorods functionalized with an alpha5beta1 ligand: a simple and robust nanosystem for early bladder cancer detection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2381.

Early detection and removal of bladder cancer in patients is crucial to prevent tumor recurrence and progression. Because current imaging techniques may fail to detect small lesions of in situ carcinomas, patients with bladder cancer often relapse after initial diagnosis, thereby requiring frequent follow-up and treatments. In an attempt to obtain a sensitive and high-resolution imaging modality for bladder cancer, we have developed a photoacoustic imaging approach based on the use of PEGylated gold nanorods (GNRs) as a contrast agent, functionalized with the peptide cyclic [CphgisoDGRG] (Iso4), a selective ligand of α5β1 integrin expressed by bladder cancer cells. This product (called GNRs@PEG-Iso4) was produced by a simple two-step procedure based on GNRs activation with lipoic acid-polyethyleneglycol(PEG-5KDa)-maleimide and functionalization with peptide Iso4. Biochemical and biological studies showed that GNRs@PEG-Iso4 can efficiently recognize purified integrin α5β1 and α5β1-positive bladder cancer cells. GNRs@PEG-Iso4 was stable and did not aggregate in urine or in 5

A B S T R A C T Background and objectives: Gold nanorod-assisted photothermal therapy (GNR-PTT) is a cancer treatment whereby GNRs incorporated into the tumour act as photo-absorbers to elevate the thermal destruction effect. In the case of bladder, there are few possible routes to target the tumour with GNRs, namely peri/intra-tumoural injection and intravesical instillation of GNRs. These two approaches lead to different GNR distribution inside the tumour and can affect the treatment outcome.Methodology: The present study investigates the effects of heterogeneous GNR distribution in a typical setup of GNR-PTT. Three cases were considered. Case 1 considered the GNRs at the tumour centre, while Case 2 represents a hypothetical scenario where GNRs are distributed at the tumour periphery; these two cases represent intratumoural accumulation with different degree of GNR spread inside the tumour. Case 3 is achieved when GNRs target the exposed tumoural surface that is invading the bladder wall, when they are delivered by intravesical instillation.Results: Results indicate that for a laser power of 0.6 W and GNR volume fraction of 0.01%, Case 2 and 3 were successful in achieving complete tumour eradication after 330 and 470 s of laser irradiation, respectively. Case 1 failed to form complete tumour damage when the GNRs are concentrated at the tumour centre but managed to produce complete tumour damage if the spread of GNRs is wider. Results from Case 2 also demonstrated a different heating profile from Case 1, suggesting that thermal ablation during GNR-PTT is dependant on the GNRs distribution inside the tumour. Case 3 shows similar results to Case 2 whereby gradual but uniform heating is observed. Cases 2 and 3 show that uniformly heating the tumour can reduce damage to the surrounding tissues.Conclusions: Different GNR distribution associated with the different methods of introducing GNRs to the bladder during GNR-PTT affect the treatment outcome of bladder cancer in mice. Insufficient spreading during intratumoural injection of GNRs can render the treatment ineffective, while administered via in-travesical instillation. GNR distribution achieved through intravesical instillation present some advantages over intratumoural injection and is worthy of further exploration.(c) 2023 The Authors. Published by Elsevier B.V.This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )

Photoacoustics (PA) is gaining increasing credit among biomolecular imaging methodologies by virtue of its poor invasiveness, deep penetration, high spatial resolution, and excellent endogenous contrast, without the use of any ionizing radiation. Recently, we disclosed the excellent PA response of a self-structured biocompatible nanoprobe, consisting of ternary hybrid nanoparticles with a silver core and a melanin component embedded into a silica matrix. Although preliminary evidence suggested a crucial role of the Ag sonophore and the melanin-containing nanoenvironment, whether and in what manner the PA response is controlled and affected by the self-structured hybrid nanosystems remained unclear. Because of their potential as multifunctional platforms for biomedical applications, a detailed investigation of the metal-polymer-matrix interplay underlying the PA response was undertaken to understand the physical and chemical factors determining the enhanced response and to optimize the architecture, composition, and performance of the nanoparticles for efficient imaging applications. Herein, we provide the evidence for a strong synergistic interaction between eumelanin and Ag which suggests an important role in the in situ-generated metal-organic interface. In particular, we show that a strict ratio between melanin and silver precursors and an accurate choice of metal nanoparticle dimension and the kind of metal are essential for achieving strong enhancements of the PA response. Systematic variation of the metal/melanin component is thus shown to offer the means of tuning the stability and intensity of the photoacoustic response for various biomedical and theranostic applications.

Non-invasive longitudinal imaging of osseointegration of bone implants is essential to ensure a comprehensive, physical and biochemical understanding of the processes related to a successful implant integration and its long-term clinical outcome. This study critically reviews the present imaging techniques that may play a role to assess the initial stability, bone quality and quantity, associated tissue remodelling dependent on implanted material, implantation site (surrounding tissues and placement depth), and biomarkers that may be targeted. An updated list of biodegradable implant materials that have been reported in the literature, from metal, polymer and ceramic categories, is provided with reference to the use of specific imaging modalities (computed tomography, positron emission tomography, ultrasound, photoacoustic and magnetic resonance imaging) suitable for longitudinal and non-invasive imaging in humans. The advantages and disadvantages of the single imaging modality are discussed with a special focus on preclinical imaging for biodegradable implant research. Indeed, the investigation of a new implant commonly requires histological examination, which is invasive and does not allow longitudinal studies, thus requiring a large number of animals for preclinical testing. For this reason, an update of the multimodal and multi-parametric imaging capabilities will be here presented with a specific focus on modern biomaterial research.

Gold nanorods (GNRs) showed to be a suitable contrast agent in photoacoustics (PA), and are able to provide a tunable absorption contrast against background tissue, while a detectable PA signal can be generated from highly localized and targeted areas. A crucial issue for these imaging techniques is represented by the discrimination between exogenous and endogenous contrast and the assessment of the real PA signal magnitude. The application of image resolution/unmixing methods was implemented and optimized to recover the relative magnitude spectra and distribution maps of image constituents of the biological sample based on multivariate analysis (multivariate curve resolution-alternating least squares, MCR-ALS) in the presence of GNRs with tunable absorption properties. The proposed data analysis methodology is demonstrated on real PA images from experimental animal models and ex-vivo preparations.