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.

Inhalable Formulation Based on Lipid-Polymer Hybrid Nanoparticles for the Macrophage Targeted Delivery of Roflumilast.

Here, novel lipid-polymer hybrid nanoparticles (LPHNPs), targeted to lung macrophages, were realized as potential carriers for Roflumilast administration in the management of chronic obstructive pulmonary disease (COPD). To achieve this, Roflumilast-loaded fluorescent polymeric nanoparticles, based on a polyaspartamide-polycaprolactone graft copolymer, and lipid vesicles, made from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-distearoyl-sn-glycero-phosphoethanolamine-N-(polyethylene glycol)-mannose, were properly combined using a two-step method, successfully obtaining Roflumilast-loaded hybrid fluorescent nanoparticles (Man-LPHFNPs@Roflumilast). These exhibit colloidal size and a negative ζ potential, 50 wt % phospholipids, and a core-shell-type morphology; they slowly release the entrapped drug in a simulated physiological fluid. The surface analysis also demonstrated their high surface PEG density, which confers mucus-penetrating properties. Man-LPHFNPs@Roflumilast show high cytocompatibility toward human bronchial epithelium cells and macrophages and are uptaken by the latter through an active mannose-mediated targeting process. To achieve an inhalable formulation, the nano-into-micro strategy was applied, encapsulating Man-LPHFNPs@Roflumilast in poly(vinyl alcohol)/leucine-based microparticles by spray-drying.

Development of polymer-based nanoparticles for zileuton delivery to the lung: PMeOx and PMeOzi surface chemistry reduces interactions with mucins.

In this paper, two amphiphilic graft copolymers were synthesized by grafting polylactic acid (PLA) as hydrophobic chain and poly(2-methyl-2-oxazoline) (PMeOx) or poly(2-methyl-2-oxazine) (PMeOzi) as hydrophilic chain, respectively, to a backbone of α,ß-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA). These original graft copolymers were used to prepare nanoparticles delivering Zileuton in inhalation therapy. Among various tested methods, direct nanoprecipitation proved to be the best technique to prepare nanoparticles with the smallest dimensions, the narrowest dimensional distribution and a spherical shape. To overcome the size limitations for administration by inhalation, the nano-into-micro strategy was applied, encapsulating the nanoparticles in water-soluble mannitol-based microparticles by spray-drying. This process has allowed to produce spherical microparticles with the proper size for optimal lung deposition, and, once in contact with fluids mimicking the lung district, able to dissolve and release non-aggregated nanoparticles, potentially able to spread through the mucus, releasing about 70% of the drug payload in 24 h.

Novel dual-flow perfusion bioreactor for in vitro pre-screening of nanoparticles delivery: design, characterization and testing.

An advanced dual-flow perfusion bioreactor with a simple and compact design was developed and evaluated as a potential apparatus to reduce the gap between animal testing and drug administration to human subjects in clinical trials. All the experimental tests were carried out using an ad hoc Poly Lactic Acid (PLLA) scaffold synthesized via Thermally Induced Phase Separation (TIPS). The bioreactor shows a tunable radial flow throughout the microporous matrix of the scaffold. The radial perfusion was quantified both with permeability tests and with a mathematical model, applying a combination of Darcy's Theory, Bernoulli's Equation, and Poiseuille's Law. Finally, a diffusion test allowed to investigate the efficacy of the radial flow using Polymeric Fluorescent Nanoparticles (FNPs) mimicking drug/colloidal carriers. These tests confirmed the ability of our bioreactor to create a uniform distribution of particles inside porous matrices. All the findings candidate our system as a potential tool for drug pre-screening testing with a cost and time reduction over animal models.

Development of New Targeted Inulin Complex Nanoaggregates for siRNA Delivery in Antitumor Therapy.

Here, a novel strategy of formulating efficient polymeric carriers based on the already described INU-IMI-DETA for gene material whose structural, functional, and biological properties can be modulated and improved was successfully investigated. In particular, two novel derivatives of INU-IMI-DETA graft copolymer were synthesized by chemical functionalisation with epidermal growth factor (EGF) or polyethylenglycol (PEG), named INU-IMI-DETA-EGF and INU-IMI-DETA-PEG, respectively, in order to improve the performance of already described "inulin complex nanoaggregates" (ICONs). The latter were thus prepared by appropriately mixing the two copolymers, by varying each component from 0 to 100 wt% on the total mixture, named EP-ICONs. It was seen that the ability of the INU-IMI-DETA-EGF/INU-IMI-DETA-PEG polymeric mixture to complex siGL3 increases with the increase in the EGF-based component in the EP-ICONs and, for each sample, with the increase in the copolymer:siRNA weight ratio (R). On the other hand, the susceptibility of loaded siRNA towards RNase decreases with the increase in the pegylated component in the polymeric mixture. At all R values, the average size and the zeta potential values are suitable for escaping from the RES system and suitable for prolonged intravenous circulation. By means of biological characterisation, it was shown that MCF-7 cells are able to internalize mainly the siRNA-loaded into EGF-decorated complexes, with a significant difference from ICONs, confirming its targeting function. The targeting effect of EGF on EP-ICONs was further demonstrated by a competitive cell uptake study, i.e., after cell pre-treatment with EGF. Finally, it was shown that the complexes containing both EGF and PEG are capable of promoting the internalisation and therefore the transfection of siSUR, a siRNA acting against surviving mRNA, and to increase the sensitivity to an anticancer agent, such as doxorubicin.

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.

Spray-Drying, Solvent-Casting and Freeze-Drying Techniques: a Comparative Study on their Suitability for the Enhancement of Drug Dissolution Rates.

PURPOSE: Solid dispersions (SDs) represent the most common formulation technique used to increase the dissolution rate of a drug. In this work, the three most common methods used to prepare SDs, namely spray-drying, solvent-casting and freeze-drying, have been compared in order to investigate their effect on increasing drug dissolution rate. METHODS: Three formulation strategies were used to prepare a polymer mixture of polyvinyl-alcohol (PVA) and maltodextrin (MDX) as SDs loaded with the following three model drugs, all of which possess a poor solubility: Olanzapine, Dexamethasone, and Triamcinolone acetonide. The SDs obtained were analysed and compared in terms of drug particle size, drug-loading capacity, surface homogeneity, and dissolution profile enhancement. Physical-chemical characterisation was conducted on pure drugs, as well as the formulations made, by way of thermal analysis and infrared spectroscopy. RESULT: The polymers used were able to increase drug saturation solubility. The formulation strategies affected the drug particle size, with the solvent-casting method resulting in more homogenous particle size and distribution when compared to the other methods. The greatest enhancement in the drug dissolution rate was seen for all the samples prepared using the solvent-casting method. CONCLUSION: All of the methods used were able to increase the dissolution rate of the pure drugs alone, however, the solvent-casting method produced SDs with a higher surface homogeneity, drug incorporation capability, and faster dissolution profile than the other techniques.

Nano into Micro Formulations of Tobramycin for the Treatment of Pseudomonas aeruginosa Infections in Cystic Fibrosis.

Here, nano into micro formulations (NiMs) of tobramycin for the treatment of Pseudomonas aeruginosa airway infections in cystic fibrosis (CF) are described. NiMs were produced by spray drying a solution containing polymers or sugars and a nanometric polyanion-tobramcyin complex (PTC), able to achieve a prolonged antibiotic release. NiMs properties were compared to TOBIPodhaler(Novartis), the only one commercially available dry powder inhalatory formulation based on porous microparticles. Produced NiMs showed adequate characteristics for pulmonary administration, as spherical shape, micrometric size, and high cytocompatibility toward human bronchial epithelial cells. Contrarily to TOBIPodhaler, some of produced NiMs, thanks to their specific chemical composition, are able to facilitate the drug diffusion through the mucus secretion, achieving, at the same time, a sustained tobramycin delivery. Moreover, NiMs showed pronounced antimicrobial activity against P. aeruginosa pathogens and their biofilm, if compared to free tobramycin and TOBIPodhaler, demonstrating the potential of obtained formulations as drug delivery systems for the treatment of pulmonary infections in CF patients.

Margination of Fluorescent Polylactic Acid-Polyaspartamide based Nanoparticles in Microcapillaries In Vitro: the Effect of Hematocrit and Pressure.

The last decade has seen the emergence of vascular-targeted drug delivery systems as a promising approach for the treatment of many diseases, such as cardiovascular diseases and cancer. In this field, one of the major challenges is carrier margination propensity (i.e., particle migration from blood flow to vessel walls); indeed, binding of these particles to targeted cells and tissues is only possible if there is direct carrier-wall interaction. Here, a microfluidic system mimicking the hydrodynamic conditions of human microcirculation in vitro is used to investigate the effect of red blood cells (RBCs) on a carrier margination in relation to RBC concentration (hematocrit) and pressure drop. As model drug carriers, fluorescent polymeric nanoparticles (FNPs) were chosen, which were obtained by using as starting material a pegylated polylactic acid-polyaspartamide copolymer. The latter was synthesized by derivatization of α,ß-poly(N-2-hydroxyethyl)-d,l-aspartamide (PHEA) with Rhodamine (RhB), polylactic acid (PLA) and then poly(ethyleneglycol) (PEG) chains. It was found that the carrier concentration near the wall increases with increasing pressure drop, independently of RBC concentration, and that the tendency for FNP margination decreases with increasing hematocrit. This work highlights the importance of taking into account RBC-drug carrier interactions and physiological conditions in microcirculation when planning a drug delivery strategy based on systemically administered carriers.

Pegylated Polyaspartamide-Polylactide-Based Nanoparticles Penetrating Cystic Fibrosis Artificial Mucus.

Here, the preparation of mucus-penetrating nanoparticles for pulmonary administration of ibuprofen in patients with cystic fibrosis is described. A fluorescent derivative of α,ß-poly(N-2-hydroxyethyl)-D,L-aspartamide is synthesized by derivatization with rhodamine, polylactide, and poly(ethylene glycol), to obtain polyaspartamide-polylactide derivatives with different degrees of pegylation. Starting from these copolymers, fluorescent nanoparticles with different poly(ethylene glycol) content, empty and loaded with ibuprofen, showed spherical shape, colloidal size, slightly negative ζ potential, and biocompatibility toward human bronchial epithelial cells. The high surface poly(ethylene glycol) density of fluorescent nanoparticles and poly(ethylene glycol) brush-like conformation assumed on their surface, conferred to pegylated nanoparticles the mucus-penetrating properties, properly demonstrated by assessing their ability to avoid interactions with mucus components and to penetrate cystic fibrosis artificial mucus. Finally, ibuprofen release profile and uptake capacity within human bronchial epithelial cells in the presence of cystic fibrosis artificial mucus showed how these mucus-penetrating nanoparticles could rapidly diffuse through the mucus barrier reaching the mucosal surface, where they could offer a sustained delivery of ibuprofen at the site of disease.

Improvements in Rational Design Strategies of Inulin Derivative Polycation for siRNA Delivery.

The advances of short interfering RNA (siRNA)-mediated therapy provide a powerful option for the treatment of many diseases, including cancer, by silencing the expression of targeted genes involved in the progression of the pathology. On this regard, a new pH-responsive polycation derived from inulin, Inulin-g-imidazole-g-diethylenetriamine (INU-IMI-DETA), was designed and employed to produce INU-IMI-DETA/siRNA "Inulin COmplex Nanoaggregates" (ICONs). The experimental results showed that INU-IMI-DETA exhibited strong cationic characteristics and high solubility in the pH range 3-5 and self-aggregation triggered by pH increase and physiological salt concentration. INU-IMI-DETA showed as well a high buffering capacity in the endosomal pH range of 7.4-5.1. In the concentration range between 25 and 1000 µg/mL INU-IMI-DETA had no cytotoxic effect on breast cancer cells (MCF-7) and no lytic effect on human red blood cells. ICONs were prepared by two-step procedure involving complexation and precipitation into DPBS buffer (pH 7.4) to produce siRNA-loaded nanoaggregates with minimized surface charge and suitable size for parenteral administration. Bafilomycin A1 inhibited transfection on MCF-7 cells, indicating that the protonation of the imidazole groups in the endolysosome pathway favors the escape of the system from endolysosomal compartment, increasing the amount of siRNA that can reach the cytoplasm.

Biotin-Containing Reduced Graphene Oxide-Based Nanosystem as a Multieffect Anticancer Agent: Combining Hyperthermia with Targeted Chemotherapy.

Among the relevant properties of graphene derivatives, their ability of acting as an energy-converting device so as to produce heat (i.e., thermoablation and hyperthermia) was more recently taken into account for the treatment of solid tumors. In this pioneering study, for the first time, the in vitro RGO-induced hyperthermia was assessed and combined with the stimuli-sensitive anticancer effect of a biotinylated inulin-doxorubicin conjugate (CJ-PEGBT), hence, getting to a nanosystem endowed with synergic anticancer effects and high specificity. CJ-PEGBT was synthesized by linking pentynoic acid and citraconic acid to inulin. The citraconylamide pendants, used as pH reversible spacer, were exploited to further conjugate doxorubicin, whereas the alkyne moiety was orthogonally functionalized with an azido PEG-biotin derivative by copper(II) catalyzed 1,3-dipolar cycloaddition. DSC measures, AFM, and UV spectrophotometry were employed to systematically investigate adsorption of CJ-PEGBT onto RGO and its physicochemical stability in aqueous media, demonstrating that a stable π-staked nanosystem can be obtained. In vitro tests using cancer breast cells (MCF-7) showed the ability of the RGO/CJ-PEGBT of efficiently killing cancer cells both via a selective laser beam thermoablation and hyperthermia-triggered chemotherapy. If compared with the nonbiotinylated nanosystem, including virgin RGO and the free conjugate, RGO/CJ-PEGBT is endowed with a smart combination of properties which warrant potential as an anticancer nanomedicine.

Nanocomplexes for gene therapy of respiratory diseases: Targeting and overcoming the mucus barrier.

Gene therapy, i.e. the delivery and expression of therapeutic genes, holds great promise for congenital and acquired respiratory diseases. Non-viral vectors are less toxic and immunogenic than viral vectors, although they are characterized by lower efficiency. However, they have to overcome many barriers, including inflammatory and immune mediators and cells. The respiratory and airway epithelial cells, the main target of these vectors, are coated with a layer of mucus, which hampers the effective reaching of gene therapy vectors carrying either plasmid DNA or small interfering RNA. This barrier is thicker in many lung diseases, such as cystic fibrosis. This review summarizes the most important advancements in the field of non-viral vectors that have been achieved with the use of nanoparticulate (NP) systems, composed either of polymers or lipids, in the lung gene delivery. In particular, different strategies of targeting of respiratory and airway lung cells will be described. Then, we will focus on the two approaches that attempt to overcome the mucus barrier: coating of the nanoparticulate system with poly(ethylene glycol) and treatment with mucolytics. Our conclusions are: 1) Ligand and physical targeting can direct therapeutic gene expression in specific cell types in the respiratory tract; 2) Mucopenetrating NPs are endowed with promising features to be useful in treating respiratory diseases and should be now advanced in pre-clinical trials. Finally, we discuss the development of such polymer- and lipid-based NPs in the context of in vitro and in vivo disease models, such as lung cancer, as well as in clinical trials.

Inulin-Ethylenediamine Coated SPIONs Magnetoplexes: A Promising Tool for Improving siRNA Delivery.

PURPOSE: An inulin based polycation (Inu-EDA) has been synthesized by the grafting of ethylenediamine molecules onto inulin backbone. The obtained inulin copolymer has been though to coat SPIONs (IC-SPIONs) and obtain stable magnetoplexes by complexation of IC-SPIONs with a model duplexed siRNA, for improving oligonucleotide transfection efficiency. METHODS: The physical-chemical characteristics of IC-SPIONs and IC-SPIONs/siRNA magnetoplexes have been investigated by scanning and transmission electron microscopies, dynamic light scattering, FT-IR and qualitative surface elementary analysis. Cell compatibility and internalization in vitro of IC-SPIONs have been evaluated by MTS and fluorescence microscopy respectively on cancer (HCT116) and normal human (16HBE) cells. The efficiency of gene silencing effect of magnetoplexes was studied on both tumoral (JHH6) and non tumoral (16HBE) cell lines also by applying an external magnet. RESULTS: IC-SPIONs showed dimension of 30 nm and resulted cytocompatible on the tested cell lines; in the presence of an external magnet, the magnetic force enhanced the IC-SPIONs uptake inside cells. Magnetically improved transfection was observed in 16HBE cells under magnetofective conditions, in accordance with the IC-SPIONs uptake enhancement in the presence of an external magnet. CONCLUSIONS: These findings support the potential application of this system as a magnetically targeted drug delivery system. Graphical Abstract Magnetically improved siRNA transfection in cells under magnetofective conditions upon uptake enhancement of IC-SPIONs in the presence of an external magnet.

Polyaspartamide-Polylactide Graft Copolymers with Tunable Properties for the Realization of Fluorescent Nanoparticles for Imaging.

Here, the synthesis and the characterization of novel amphiphilic graft copolymers with tunable properties, useful in obtaining polymeric fluorescent nanoparticles for application in imaging, are described. These copolymers are obtained by chemical conjugation of rhodamine B (RhB) moieties, polylactic acid (PLA), and O-(2-aminoethyl)-O'-methyl poly(ethylene glycol) (PEG) on α,ß-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA). In particular, PHEA is first functionalized with RhB to obtain PHEA-RhB with a derivatization degree in RhB (DDRhB ) equal to 0.55 mol%. By varying the reaction conditions, different amounts of PLA are grafted on PHEA-RhB to obtain PHEA-RhB-PLA with DDPLA equal to 1.9, 4.0, and 6.2 mol%. Then, PEG chains are grafted on PHEA-RhB-PLA derivatives to obtain PHEA-RhB-PLA-PEG graft copolymers. The preparation of polymeric fluorescent nanoparticles with tunable properties and spherical shape is described by using PHEA-RhB-PLA-PEG with DD in PLA and PEG equal to 4.0 and 4.9 mol%, by following easily scaling up processes, such as emulsion-solvent evaporation and high pressure homogenization (HPH)-solvent evaporation techniques.

When functionalization of PLA surfaces meets Thiol-Yne photochemistry: case study with antibacterial polyaspartamide derivatives.

In this work we wish to report on the covalent functionalization of polylactide (PLA) surfaces by photoradical thiol-yne to yield antibacterial surfaces. At first, hydrophilic and hydrophobic thiol fluorescent probes are synthesized and used to study and optimize the conditions of ligation on alkyne-PLA surfaces. In a second part, a new antibacterial polyaspartamide copolymer is covalently grafted. The covalent surface modification and the density of surface functionalization are evaluated by SEC and XPS analyses. No degradation of PLA chains is observed, whereas covalent grafting is confirmed by the presence of S2p and N1s signals. Antiadherence and antibiofilm activities are assessed against four bacterial strains, including Gram-negative and Gram-positive bacteria. A strong activity is observed with adherence reduction factors superior to 99.98% and biofilm formation decreased by 80%. Finally, in vitro cytocompatibility tests of the antibacterial surfaces are performed with L929 murine fibroblasts and show cell viability without promoting proliferation.

Effects in cigarette smoke stimulated bronchial epithelial cells of a corticosteroid entrapped into nanostructured lipid carriers.

BACKGROUND: Nanomedicine studies have showed a great potential for drug delivery into the lung. In this manuscript nanostructured lipid carriers (NLC) containing Fluticasone propionate (FP) were prepared and their biocompatibility and effects in a human bronchial epithelial cell line (16-HBE) stimulated with cigarette smoke extracts (CSE) were tested. RESULTS: Biocompatibility studies showed that the NLC did not induce cell necrosis or apoptosis. Moreover, it was confirmed that CSE increased intracellular ROS production and TLR4 expression in bronchial epithelial cells and that FP-loaded NLC were more effective than free drug in modulating these processes. Finally, the nanoparticles increased GSH levels improving cell protection against oxidative stress. CONCLUSIONS: The present study shows that NLC may be considered a promising strategy to improve corticosteroid mediated effects in cellular models associated to corticosteroid resistance. The NLC containing FP can be considered good systems for dosage forms useful for increasing the effectiveness of fluticasone decreasing its side effects.

Rapamycin-based inhaled therapy for potential treatment of COPD-related inflammation: production and characterization of aerosolizable nano into micro (NiM) particles.

Our paper describes the production and characterization of inhalable microparticles loaded with nanoparticles for the lung administration of rapamycin (Rapa). In detail, core-shell lipid/polymer hybrid nanoparticles loaded with Rapa (Rapa@Man-LPHNPs) were produced with mean size of about 128 nm and slightly negative ζ potential (-13.8 mV). A fluorescent graft polyaspartamide-poly(lactic-co-glycolic acid) copolymer (PHEA-g-RhB-g-PLGA) for use as the polymeric core was obtained by nanoprecipitation, while an appropriate mixture of DPPC and mannosylated phospholipid (DSPE-PEG2000-Man) was used to provide the macrophage-targeting lipid shell. The successful formation of Rapa@Man-LPHNPs was confirmed by TEM and DSC analyses. The loaded drug (4.3 wt% of the total weight) was slowly released from the polymeric core and protected from hydrolysis, with the amount of intact drug after 24 h of incubation in the medium being equal to 74 wt% (compared to 40% when the drug is freely incubated at the same concentration). To obtain a formulation administrable by inhalation, Rapa@Man-LPHNPs were entrapped inside PVA : LEU microparticles by using the nano into micro (NiM) strategy, specifically by spray drying (SD) in the presence of a pore-forming agent. In this way, NiM particles with geometric and theoretical aerodynamic diameters equal to 4.52 µm and 3.26 µm, respectively, were obtained. Furthermore, these particles showed optimal nebulization performance, having an FPF and an MMAD equal to 27.5% and 4.3 µm, respectively.

Microporous Fluorescent Poly(D,L-lactide) Acid-Carbon Nanodot Scaffolds for Bone Tissue Engineering Applications.

In this study, we introduce novel microporous poly(D,L-lactide) acid-carbon nanodot (PLA-CD) nanocomposite scaffolds tailored for potential applications in image-guided bone regeneration. Our primary objective was to investigate concentration-dependent structural variations and their relevance to cell growth, crucial aspects in bone regeneration. The methods employed included comprehensive characterization techniques such as DSC/TGA, FTIR, rheological, and degradation assessments, providing insights into the scaffolds' thermoplastic behavior, microstructure, and stability over time. Notably, the PLA-CD scaffolds exhibited distinct self-fluorescence, which persisted after 21 days of incubation, allowing detailed visualization in various multicolor modalities. Biocompatibility assessments were conducted by analyzing human adipose-derived stem cell (hADSC) growth on PLA-CD scaffolds, with results substantiated through cell viability and morphological analyses. hADSCs reached a cell viability of 125% and penetrated throughout the scaffold after 21 days of incubation. These findings underscore the scaffolds' potential in bone regeneration and fluorescence imaging. The multifunctional nature of the PLA-CD nanocomposite, integrating diagnostic capabilities with tunable properties, positions it as a promising candidate for advancing bone tissue engineering. Our study not only highlights key aspects of the investigation but also underscores the scaffolds' specific application in bone regeneration, providing a foundation for further research and optimization in this critical biomedical field.

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.