Ultrasmall Carbon Nanodots as Theranostic Nanoheaters for Precision Breast Cancer Phototherapy: Establishing the Translational Potential in Tumor-in-a-Dish Models.

This study investigates the remarkable attributes of sulfur-doped carbon nanodots (CDs) synthesized in high yield and a narrow size distribution (4.8 nm). These CDs exhibit notable features, including potential bioelimination through renal clearance and efficient photothermal conversion in the near-infrared region with multicolor photoluminescence across the visible spectrum. Our research demonstrates high biocompatibility and effective near-infrared (NIR)-triggered photothermal toxicity when targeting mammospheres and patient-derived tumor organoids. Moreover, the study delves into the intricate cellular responses induced by CD-mediated hyperthermia. This involves efficient tumor mass death, activation of the p38-mitogen-activated protein kinase (MAPK) pathway, and upregulation of genes associated with apoptosis, hypoxia, and autophagy. The interaction of CDs with mammospheres reveals their ability to penetrate the complex microenvironment, impeded at 4 °C, indicating an energy-dependent endocytosis mechanism. This observation underscores the CDs' potential for targeted drug delivery, particularly in anticancer therapeutics. This investigation contributes to understanding the multifunctional properties of sulfur-doped CDs and highlights their promising applications in cancer therapeutics. Utilizing 3-D tumor-in-a-dish patients' organoids enhances translational potential, providing a clinically relevant platform for assessing therapeutic efficacy in a context mirroring the physiological conditions of cancerous tissues.

Polyamidoamine-Carbon Nanodot Conjugates with Bioreducible Building Blocks: Smart Theranostic Platforms for Targeted siRNA Delivery.

This study focuses on designing hybrid theranostic nanosystems, utilizing gadolinium-doped carbon nanodots decorated with bioreducible amphoteric polyamidoamines (PAAs). The objective is to synergize the exceptional theranostic properties of gadolinium-doped carbon nanodots (CDs) with the siRNA complexation capabilities of PAAs. Linear copolymeric polyamidoamines, based on N,N'-bis(acryloyl)cystamine, arginine, and agmatine, were synthesized, resulting in three distinct amphoteric copolymers. Notably, sulfur bridges within the PAA repeating units confer pronounced susceptibility to glutathione-mediated degradation─a key attribute in the tumor microenvironment. This pathway enables controlled and stimuli-responsive siRNA release, theoretically providing precise spatiotemporal control over therapeutic interventions. The selected PAA, conjugated with CDs using the redox-sensitive spacer cystamine, formed the CDs-Cys-PAA conjugate with superior siRNA complexing capacity. Stable against polyanion exchange, the CDs-Cys-PAA/siRNA complex released siRNA in the presence of GSH. In vitro studies assessed cytocompatibility, internalization, and gene silencing efficacy on HeLa, MCF-7, and 16HBE cell lines.

Controlled delivery of sildenafil by ß-Cyclodextrin-decorated sulfur-doped carbon nanodots: a synergistic activation of ROS signaling in tumors overexpressing PDE-5.

Fluorescent sulfur- and nitrogen-doped carbon nanodots (CDs) are zero-dimensional nanoparticles that mediate ROS production in cancer cells, displaying inherent anticancer properties. Thus, they have been proposed as nanotheranostic tools useful in image-guided cancer therapy. Here, we try to show that cancerous cells (high PDE-5 expression) receiving sildenafil delivered by CDs-based nanostructures promote positive reinforcement of PDE-5-mediated cell death via the overexpression of genes involved in the production of ROS. We explored the regioselective Huisgen cycloaddition between azide-ß-cyclodextrin and CDs-alkyne to synthetize homogeneous nanostructures, named CDs-PEG4-ß-Cdx, consisting of CDs functionalized at the surface with ß-cyclodextrins capable of including high amount drugs such as sildenafil (>20 % w/w), and releasing them in a controlled manner. We investigated how CDs-PEG4-ß-Cdx bearing sildenafil enter cells, enhancing ROS production and cell death specifically in cancer cells overexpressing PDE-5. These nanoplatforms go beyond the bounds of EPR-based nanomedicines in which carriers are conceived as inert vehicles of toxic drugs. Our findings enable the development of clever anticancer nanoplatforms that synergistically combine nanomedicines that perturb the mitochondrial electron transport chain (ROS production) with PDE-5 inhibitors which trigger oxidative stress specifically in cancer cells regardless of their location.

Gadolinium-Doped Carbon Nanodots as Potential Anticancer Tools for Multimodal Image-Guided Photothermal Therapy and Tumor Monitoring.

This study focuses on the synthesis and characterization of gadolinium-doped carbon nanodots (CDs-Gd) and their potential applications in multimodal imaging and precision cancer therapy. CDs-Gd were synthesized through a solvothermal decomposition method combining citric acid, GdCl3, and urea. The incorporation of Gd3+ ions within the carbonaceous structure resulted in stable CDs-Gd with a peculiar architecture that retained optical and paramagnetic properties. Combined characterization techniques confirmed the presence of pH-sensitive COOH functions on the CDs-Gd surface along with the unique lattice structure induced by Gd3+ doping. The optical properties of CDs-Gd exhibited a tunable emission spectrum displaying blue-green emission with pH-dependent behavior. Additionally, CDs-Gd exhibited contrast-enhancing properties in T1-weighted magnetic resonance imaging (MRI) experiments. MRI acquisitions at different Gd3+ concentrations and pH values demonstrated the potential of CDs-Gd as contrast agents for monitoring pH changes in an aqueous environment. We found that the relaxivity of CDs-Gd at pH 5.5 (tumor, 11.3 mM-1 s-1) is roughly 3-fold higher than that observed at pH 7.4 (physiological, 5.0 mM-1 s-1) and outperformed clinical standards such as γ-butyrol (3.3 mM-1 s-1). Monitoring pH changes in tumor microenvironment (TME) is crucial for evaluating the effectiveness of anticancer treatments and understanding tumor progression. Furthermore, CDs-Gd demonstrated concentration-dependent photothermal conversion ability in the near-infrared (NIR) region, allowing for efficient heat generation under laser irradiation. This indicates the potential application of CDs-Gd in image-guided photothermal therapy (IG-PTT) for cancer treatment. The in vitro studies on MCF-7 (breast cancer) and 16-HBE (healthy bronchial epithelium) cell lines demonstrated that CDs-Gd exhibited high biocompatibility (cell viability >80%). However, upon NIR activation, they showed potent anticancer effects by inhibiting tumor cell proliferation and inducing apoptosis selectively in cancer cells. In conclusion, the synthesized CDs-Gd nanoparticles possess unique optical, photothermal, and MRI contrast properties, making them promising candidates for multimodal imaging-guided precision cancer therapy applications.

Galactosylated Polymer/Gold Nanorods Nanocomposites for Sustained and Pulsed Chemo-Photothermal Treatments of Hepatocarcinoma.

In this paper, we propose a rational design of a hybrid nanosystem capable of locally delivering a high amount of hydrophobic anticancer drugs (sorafenib or lenvatinib) and heat (hyperthermia) in a remote-controlled manner. We combined in a unique nanosystem the excellent NIR photothermal conversion of gold nanorods (AuNRs) with the ability of a specially designed galactosylated amphiphilic graft copolymer (PHEA-g-BIB-pButMA-g-PEG-GAL) able to recognize hepatic cells overexpressing the asialoglycoprotein receptor (ASGPR) on their membranes, thus giving rise to a smart composite nanosystem for the NIR-triggered chemo-phototherapy of hepatocarcinoma. In order to allow the internalization of AuNRs in the hydrophobic core of polymeric nanoparticles, AuNRs were coated with a thiolated fatty acid (12-mercaptododecanoic acid). The drug-loaded hybrid nanoparticles were prepared by the nanoprecipitation method, obtaining nanoparticles of about 200 nm and drug loadings of 9.0 and 5.4% w/w for sorafenib and lenvatinib, respectively. These multifunctional nanosystems have shown to convert NIR radiation into heat and release charged drugs in a remote-controlled manner. Then, the biocompatibility and synergistic effects of a chemo-phototherapy combination, as well the receptor-mediated internalization, were evaluated by an in vitro test on HepG2, HuH7, and NHDF. The results indicate that the proposed nanoparticles can be considered to be virtuous candidates for an efficient and selective dual-mode therapy of hepatocarcinoma.

Cholesterol-Inulin Conjugates for Efficient SN38 Nuclear Delivery: Nanomedicines for Precision Cancer Therapy.

An amphiphilic inulin-thiocholesterol conjugate (INU-Cys-TC) was strategically designed as a biodegradable core-shell nanocarrier of 7-ethyl-10-hydroxy-camptothecin (SN38) to enhance its solubility and stability in aqueous media, thus exploiting its brilliant anticancer effect. INU-Cys-TC was designed to have the hydrophilic inulin backbone (external shell) partially functionalized with hydrophobic thiocholesterol moieties (internal core) through a biodegradable disulfide bond due to cysteamine bridges. Thiocholesterol moieties impair redox-sensitive self-assembling abilities, yielding to nano-sized micelles in aqueous media capable of efficiently encapsulating a high amount of SN38 (DL = 8.1%). Micelles (INU-Cys-TC@SN38) were widely characterized, demonstrating an effective and stable delivery strategy to overcome the poor water-solubility of SN38. SN38-loaded micelles showed a gradual and prolonged release of SN38 over time, and a cell- and time-dependent cytotoxicity. In particular, we show that micelles efficiently deliver SN38 inside cell nuclei, and, compared to normal cell lines, they can also enter cancer cells by endo-lysosomes, where a complete degradation can occur releasing the drug payload. Overall, the proposed micelles appear potentially effective as nanomedicines for precision cancer therapies of colorectal and breast cancer, thus improving the SN38 therapeutic index and extending its use in a huge plethora of cancers.

Decagram-Scale Synthesis of Multicolor Carbon Nanodots: Self-Tracking Nanoheaters with Inherent and Selective Anticancer Properties.

Carbon nanodots (CDs) are a new class of carbon-based nanoparticles endowed with photoluminescence, high specific surface area, and good photothermal conversion, which have spearheaded many breakthroughs in medicine, especially in drug delivery and cancer theranostics. However, the tight control of their structural, optical, and biological properties and the synthesis scale-up have been very difficult so far. Here, we report for the first time an efficient protocol for the one-step synthesis of decagram-scale quantities of N,S-doped CDs with a narrow size distribution, along with a single nanostructure multicolor emission, high near-infrared (NIR) photothermal conversion efficiency, and selective reactive oxygen species (ROS) production in cancer cells. This allows achieving targeted and multimodal cytotoxic effects (i.e., photothermal and oxidative stresses) in cancer cells by applying biocompatible NIR laser sources that can be remotely controlled under the guidance of fluorescence imaging. Hence, our findings open up a range of possibilities for real-world biomedical applications, among which is cancer theranostics. In this work, indocyanine green is used as a bidentate SOx donor which has the ability to tune surface groups and emission bands of CDs obtained by solvothermal decomposition of citric acid and urea in N,N-dimethylformamide. The co-doping implies various surface states providing transitions in the visible region, thus eliciting a tunable multicolor emission from blue to red and excellent photothermal efficiency in the NIR region useful in bioimaging applications and image-guided anticancer phototherapy. The fluorescence self-tracking capability of SOx-CDs reveals that they can enter cancer cells more quickly than healthy cell lines and undergo a different intracellular fate after cell internalization. This could explain why sulfur doping entails pro-oxidative activities by triggering more ROS generation in cancer cells when compared to healthy cell lines. We also find that oxidative stress can be locally enhanced under the effects of a NIR laser at moderate power density (2.5 W cm-2). Overall, these findings suggest that SOx-CDs are endowed with inherent drug-independent cytotoxic effects toward cancer cells, which would be selectively enhanced by external NIR light irradiation and helpful in precision anticancer approaches. Also, this work opens a debate on the role of CD surface engineering in determining nanotoxicity as a function of cell metabolism, thus allowing a rational design of next-generation nanomaterials with targeted anticancer properties.

Functionalization of Metal and Carbon Nanoparticles with Potential in Cancer Theranostics.

Cancer theranostics is a new concept of medical approach that attempts to combine in a unique nanoplatform diagnosis, monitoring and therapy so as to provide eradication of a solid tumor in a non-invasive fashion. There are many available solutions to tackle cancer using theranostic agents such as photothermal therapy (PTT) and photodynamic therapy (PDT) under the guidance of imaging techniques (e.g., magnetic resonance-MRI, photoacoustic-PA or computed tomography-CT imaging). Additionally, there are several potential theranostic nanoplatforms able to combine diagnosis and therapy at once, such as gold nanoparticles (GNPs), graphene oxide (GO), superparamagnetic iron oxide nanoparticles (SPIONs) and carbon nanodots (CDs). Currently, surface functionalization of these nanoplatforms is an extremely useful protocol for effectively tuning their structures, interface features and physicochemical properties. This approach is much more reliable and amenable to fine adjustment, reaching both physicochemical and regulatory requirements as a function of the specific field of application. Here, we summarize and compare the most promising metal- and carbon-based theranostic tools reported as potential candidates in precision cancer theranostics. We focused our review on the latest developments in surface functionalization strategies for these nanosystems, or hybrid nanocomposites consisting of their combination, and discuss their main characteristics and potential applications in precision cancer medicine.

Hyaluronic acid dressing of hydrophobic carbon nanodots: A self-assembling strategy of hybrid nanocomposites with theranostic potential.

We propose a rational design of hyaluronic acid-dressed red-emissive carbon dots (CDs), with a well-structured hydrophobic core capable of locally delivering high amount doxorubicin (Doxo) (> 9% w/w) and heat (hyperthermia) in a light stimuli sensitive fashion. We combined in a unique micelle-like superstructure the peculiar optical properties of CDs (NIR photothermal conversion and red fluorescence) with the ability of hyaluronic acid (HA) shell of stabilizing nanomedicines in aqueous environment and recognizing cancer cells overexpressing CD44 receptors on their membranes, thus giving rise to smart theranostic agents useful in cancer imaging and NIR-triggered chemo-phototherapy of solid tumors. Hydrophobic CDs, named HCDs, were used as functional beads to self-assemble amphiphilic HA derivatives carrying polylactic acid side chains (HA-g-PLA), yielding to light-sensitive and biodegradable core-shell superstructures. We explored the biocompatibility and synergistic effects of chemo-phototherapy combination, together with fluorescence imaging, showing the huge potential of the proposed engineering strategy in improving efficacy. CHEMICAL COMPOUNDS.

Pressure-Dependent Tuning of Photoluminescence and Size Distribution of Carbon Nanodots for Theranostic Anticancer Applications.

Carbon nanodots (CDs) have recently attracted attention in the field of nanomedicine because of the biocompatibility, cost-effective nature, high specific surface, good near infrared (NIR) photothermal conversion into heat and tunable fluorescence properties, which have paved the way toward incorporating use of CDs into innovative anticancer theranostic platforms. However, a reliable synthesis of CDs with established and controlled physiochemical proprieties is precluded owing to the lack of full manipulation of thermodynamic parameters during the synthesis, thus limiting their use in real world medical applications. Herein, we developed a robust solvothermal protocol which allow fine controlling of temperature and pressure in order to obtain CDs with tunable properties. We obtained different CDs by modulating the operating pressure (from 8 to 18.5 bar) during the solvothermal decomposition of urea and citric acid in N,N-dimethylformamide at fixed composition. Atomic force microscopy (AFM), Fourier transform infrared (FTIR), ultraviolet-visible (UV-vis) and fluorescence spectroscopy were used to assess the role of pressure in influencing size, optical and surface properties of the obtained CDs. While preliminary biological and anticancer performance of CDs was established on the MDA-MB-231 cell line, used as triple negative breast cancer model. Our results indicate that pressure impinge on the formation of carbon nanoparticles under solvothermal conditions and impart desired optical, size distribution, surface functionalization and anticancer properties in a facile way. However, we have highlighted that a strategic surface engineering of these CDs is needed to limit the adsorption of corona proteins and also to increase the average surface diameter, avoiding a rapid renal clearance and improving their therapeutic efficacy in vivo.

Carbon Nanodots for On Demand Chemophotothermal Therapy Combination to Elicit Necroptosis: Overcoming Apoptosis Resistance in Breast Cancer Cell Lines.

BACKGROUND: Engineered luminescent carbon nanodots (CDs) are appealing nanomaterials for cancer image-guided photothermal therapy combining near infrared (NIR)-triggered hyperthermia, imaging, and drug delivery in a single platform for efficient killing of cancer cells. This approach would allow eliciting synergistic regulated cell death (RCD) routes such as necroptosis, targeting breast cancer cells refractory to apoptosis, thus overcoming drug resistance. METHODS: We report the preparation of CDs bearing biotin as a targeting agent (CDs-PEG-BT), which are able to load high amounts of irinotecan (23.7%) to be released in a pulsed on-demand fashion. CDs-PEG-BT have narrow size distribution, stable red luminescence, and high photothermal conversion in the NIR region, allowing imaging of MDA-MB231 and MCF-7 cancer cells and killing them by photothermal and chemotherapeutic insults. RESULTS: Cellular uptake, viability profiles, and RCD gene expression analyses provided insights about the observed biocompatibility of CDs-PEG-BT, indicating that necroptosis can be induced on-demand after the photothermal activation. Besides, photothermal activation of drug-loaded CDs-PEG-BT implies both necroptosis and apoptosis by the TNFα and RIPK1 pathway. CONCLUSIONS: The controlled activation of necroptosis and apoptosis by combining phototherapy and on-demand release of irinotecan is the hallmark of efficient anticancer response in refractory breast cancer cell lines in view of precision medicine applications.

Carbon Nanodots as Functional Excipient to Develop Highly Stable and Smart PLGA Nanoparticles Useful in Cancer Theranostics.

Theranostic systems have attracted considerable attention for their multifunctional approach to cancer. Among these, carbon nanodots (CDs) emerged as luminescent nanomaterials due to their exceptional chemical properties, synthetic ease, biocompatibility, and for their photothermal and fluorescent properties useful in cancer photothermal therapy. However, premature renal excretion due to the small size of these particles limits their biomedical application. To overcome these limitations, here, hybrid poly(lactic-co-glycolic acid) (PLGA-CDs) nanoparticles with suitable size distribution and stability have been developed. CDs were decisive in the preparation of polymeric nanoparticles, not only conferring them photothermal and fluorescent properties, needed in theranostics, but also having a strategic role in the stabilization of the system in aqueous media. In fact, CDs provide stable PLGA-based nanoparticles in aqueous media and sufficient cryoprotection in combination with 1% PVP. While PLGA nanoparticles required at least 5% of sucrose. Comparing nanosystems with different CDs content, it is also evident how these positively impinge on the loading and release of the drug, favoring high drug loading (~4.5%) and a sustained drug release over 48 h. The therapeutic and imaging potentials were finally confirmed through in vitro studies on a breast cancer cell line (MDA-MB-231) using fluorescence imaging and the MTS cell viability assay.

Design of New Polyaspartamide Copolymers for siRNA Delivery in Antiasthmatic Therapy.

Here, a novel protonable copolymer was realized for the production of polyplexes with a siRNA (inhibitor of STAT6 expression in asthma), with the aim of a pulmonary administration. The polycation was synthesized by derivatization of α,ß-poly(N-2-hydroxyethyl)d,l-aspartamide (PHEA) with 1,2-Bis(3-aminopropylamino)ethane (bAPAE) in proper conditions to obtain a PHEA-g-bAPAE graft copolymer with a derivatization degree in amine (DDbAPAE%) equal to 35 mol%. The copolymer showed a proper buffering behavior, i.e., ranging between pH 5 and 7.4, to potentially give the endosomal escape of the obtained polycations. In effect, an in vitro experiment demonstrated the effect on biological membranes of the copolymer on bronchial epithelial cells (16-HBE) strongly dependent on the pH of the medium, i.e., higher at pH 5. bAPAE-based copolymers were further obtained with an increasing pegylation degree, i.e., equal to 1.9, 2.7, and 4.4 mol%, respectively. All the obtained copolymers were able to complex siRNA at a N/P ratio that decreases as the pegylation degree increases. At the same time, the tendency of polyplexes to aggregate and the capability to interact with mucin also decreases as the pegylation in the copolymer increases. Gene silencing experiments on 16-HBE showed that these copolymers have a significant role in improving the intracellular transport of naked siRNA, where the presence of PEG does not seem to hinder the cellular uptake of polyplexes. The latter obtained at polymer/siRNA weight ratio (R) equal to 10 with PHEA-g-PEG(C)-g-bAPAE also seems to be not susceptible to the presence of mucin, avoiding the polyanionic exchange of complexed siRNA, thus showing adequate behavior to be used as an effective vector for siRNA.

Folic acid-functionalized graphene oxide nanosheets via plasma etching as a platform to combine NIR anticancer phototherapy and targeted drug delivery.

PEGylated graphene oxide (GO) has shown potential as NIR converting agent to produce local heat useful in breast cancer therapy, since its suitable photothermal conversion, high stability in physiological fluids, biocompatibility and huge specific surface. GO is an appealing nanomaterial for potential clinical applications combining drug delivery and photothermal therapy in a single nano-device capable of specifically targeting breast cancer cells. However, native GO sheets have large dimensions (0.5-5 µm) such that tumor accumulation after a systemic administration is usually precluded. Herein, we report a step-by-step synthesis of folic acid-functionalized PEGylated GO, henceforth named GO-PEG-Fol, with small size and narrow size distribution (∼30 ±â€¯5 nm), and the ability of efficiently converting NIR light into heat. GO-PEG-Fol consists of a nano-GO sheet, obtained by fragmentation of GO by means of non-equilibrium plasma etching, fully functionalized with folic acid-terminated PEG2000 chains through amidic coupling and azide-alkyne click cycloaddition, which we showed as active targeting agents to selectively recognize breast cancer cells such as MCF7 and MDA-MB-231. The GO-PEG-Fol incorporated a high amount of doxorubicin hydrochloride (Doxo) (>33%) and behaves as NIR-light-activated heater capable of triggering sudden Doxo delivery inside cancer cells and localized hyperthermia, thus provoking efficient breast cancer death. The cytotoxic effect was found to be selective for breast cancer cells, being the IC50 up to 12 times lower than that observed for healthy fibroblasts. This work established plasma etching as a cost-effective strategy to get functionalized nano-GO with a smart combination of properties such as small size, good photothermal efficiency and targeted cytotoxic effect, which make it a promising candidate as photothermal agent for the treatment of breast cancer.

Highly Homogeneous Biotinylated Carbon Nanodots: Red-Emitting Nanoheaters as Theranostic Agents toward Precision Cancer Medicine.

Very recent red-emissive carbon nanodots (CDs) have shown potential as near-infrared converting tools to produce local heat useful in cancer theranostics. Besides, CDs seem very appealing for clinical applications combining hyperthermia, imaging, and drug delivery in a single platform capable of selectively targeting cancer cells. However, CDs still suffer from dramatic dot-to-dot variability issues such that a rational design of their structural, optical, and chemical characteristics for medical applications has been impossible so far. Herein, we report for the first time a simple and highly controllable layer-by-layer synthesis of biotin-decorated CDs with monodisperse size distribution, well established polymeric shell thickness, and degree of surface functionalization, endowed with strong red luminescence and the ability to convert NIR light into heat. These CDs, henceforth named CDs-PEG-BT, consist of a carbonaceous core passivated with biotin-terminated PEG2000 chains, which we demonstrate as active targeting groups to recognize cancer cells. The CDs-PEG-BT are designed to efficiently incorporate a high amount of anticancer drugs such as irinotecan (16-28%) and to act as NIR-activated nanoheaters capable of triggering local hyperthermia and massive drug release inside tumors, thus provoking sudden and efficient tumor death. The potential of the irinotecan-loaded CDs-PEG-BT (CDs-PEG-BT@IT) in fluorescence imaging was studied on 2D cultures and on complex 3D spheroids mimicking in vivo tumor architectures, showing their capability of selectively entering cancer cells through biotin receptors overexpressed in cell membranes. The efficient anticancer effect of these CDs was thoroughly assessed on multicellular 3D spheroids and patient organoids (tumor-on-a-dish preclinical models) to predict the drug response in humans in view of personalized medicine applications. CDs-PEG-BT@IT have a smart combination of properties, which pave the way to their real-world use as anticancer theranostic agents for image-guided photothermal applications.

SPIONs embedded in polyamino acid nanogels to synergistically treat tumor microenvironment and breast cancer cells.

The extremely complex tumor microenvironment (TME) in humans is the major responsible for the therapeutic failure in cancer nanomedicine. A new concept of disease-driven nanomedicine, henceforth named "Theranomics", which attempts to target cancer cells and TME on the whole, represents an attractive alternative. Herein, a nanomedicine able to co-deliver doxorubicin and a tumor suppressive proteolytic protein such as collagenase-2 was developed. We successfully obtained superparamagnetic nanogels (SPIONs/Doco@Col) via the intermolecular azide-alkyne Huisgen cycloaddition. We demonstrated that a local ECM degradation and remodeling in solid tumors by means of collagenase-2 could enhance tumor penetration of nanomedicines and the in situ sustained release of the drug payload throughout 3-D tumor spheroids up to the core (parenchyma), thus enabling a synergistic and efficient anticancer effect toward highly invasive breast tumors. We illustrate that SPIONs/Doxo@Col is also capable of reducing the invasivity of cancer cells.

Mucus and Cell-Penetrating Nanoparticles Embedded in Nano-into-Micro Formulations for Pulmonary Delivery of Ivacaftor in Patients with Cystic Fibrosis.

Here, mucus-penetrating nanoparticles (NPs) for pulmonary administration of ivacaftor in patients with cystic fibrosis (CF) were produced with the dual aim of enhancing ivacaftor delivery to the airway epithelial cells, by rapid diffusion through the mucus barrier, and at the same time, promoting ivacaftor lung cellular uptake. Pegylated and Tat-decorated fluorescent nanoparticles (FNPs) were produced by nanoprecipitation, starting from two synthetic copolymers, and showed nanometric sizes (∼70 nm), a slightly negative ζ potential, and high cytocompatibility toward human bronchial epithelium cells. After having showed the significant presence of poly(ethylene glycol) chains and Tat protein onto the FNP surface, the FNP mucus-penetrating ability, ivacaftor release profile, and lung cellular uptake were studied in the presence of CF-artificial mucus as a function of the FNP surface chemical composition. Moreover, microparticle-based pulmonary drug-delivery systems composed of mucus-penetrating FNPs loaded with ivacaftor and mannitol were prepared by using the nano-into-micro strategy and realized by spray-drying, thereby providing optimal preservation and stabilization of FNP technological and fluorescence properties.

Branched High Molecular Weight Glycopolypeptide With Broad-Spectrum Antimicrobial Activity for the Treatment of Biofilm Related Infections.

There are few therapeutic options to simultaneously tackle Staphylococcus aureus and Pseudomonas aeruginosa, two of the most relevant nosocomial and antibiotic-resistant pathogens responsible for implant, catheters and wound severe infections. The design and synthesis of polymers with inherent antimicrobial activity have gained increasing attention as a safe strategy to treat multi-drug-resistant microbes. Here, we tested the activity of a new polymeric derivative with glycopolypeptide architecture (PAA-VC) bearing l-arginine, vancomycin, and colistin as side chains acting against multiple targets, which give rise to a broad spectrum antimicrobial activity favorably combining specific and nonspecific perturbation of the bacterial membrane. PAA-VC has been tested against planktonic and established biofilms of reference strains S. aureus ATCC 25923 and P. aeruginosa ATCC 15442 and susceptible or antibiotic resistant clinical isolates of the above-mentioned microorganisms. MIC values observed for the conjugate (48-190 and 95-190 nM for P. aeruginosa and S. aureus strains, respectively) showed higher efficacy if compared with the free vancomycin (MICs within 1.07-4.28 µM) and colistin (MICs within 0.63-1.33 µM). Additionally, being highly biocompatible (IC50 > 1000, 430, and 250 µg mL-1 for PAA-VC, vancomycin and colistin respectively) high-dosage can be adopted for the eradication of infections in patients. This positively influences the anti-biofilm activity of the conjugate leading to a quasi-total eradication of established clinically relevant biofilms (inhibition >90% at 500 µg mL-1). We believe that the in vitro presented data, especially the activity against established biofilms of two relevant pathogens, the high biocompatibility and the good mucoadhesion properties, would allow the use of PAA-VC as promising candidate to successfully address emerging infections.

Enhanced adhesion and in situ photothermal ablation of cancer cells in surface-functionalized electrospun microfiber scaffold with graphene oxide.

The physicochemical characteristics of a biomaterial surface highly affect the interaction with living cells. Recently, much attention has been focused on the adhesion properties of functional biomaterials toward cancer cells, since is expected to control metastatic spread of a tumor, which is related to good probability containing the progression of disease burden. Here, we designed an implantable poly(caprolactone)-based electrospun microfiber scaffold, henceforth PCLMF-GO, to simultaneously capture and kill cancer cells by tuning physicochemical features of the hybrid surface through nitrogen plasma activation and hetero-phase graphene oxide (GO) covalent functionalization. The surface immobilization of GO implies enhanced cell adhesion and proliferation, promoting the selective adhesion of cancer cells, even if allowing cancer associated fibroblast (CAFs) capture. We also display that the functionalization with GO, thanks to the high near-infrared (NIR) absorbance, enables the discrete photothermal eradication of the captured cancer cells in situ (≈98%).

Double-Network-Structured Graphene Oxide-Containing Nanogels as Photothermal Agents for the Treatment of Colorectal Cancer.

Here, we reported the production of hyaluronic acid/polyaspartamide-based double-network nanogels for the potential treatment of colorectal carcinoma. Graphene oxide, thanks to the huge aromatic surface area, allows to easily load high amount of irinotecan (33.0% w/w) and confers to the system hyperthermic properties when irradiated with a near-infrared (NIR) laser beam. We demonstrate that the release of antitumor drug is influenced both by the pH of the external medium and the NIR irradiation process. In vitro biological studies, conducted on human colon cancer cells (HCT 116), revealed that nanogels are uptaken by the cancer cells and, in the presence of the antitumor drug, can produce a synergistic hyperthermic/cytotoxic effect. Finally, 3D experiments demonstrate that it is possible to conduct thermal ablation of solid tumors after the intratumoral administration of nanogels.