T1-Positive Mn2+-Doped Multi-Stimuli Responsive poly(L-DOPA) Nanoparticles for Photothermal and Photodynamic Combination Cancer Therapy

Multifunctional Natural and Synthetic Melanin for Bioelectronic Applications: A Review

Emerging material interest in bioelectronic applications has highlighted natural melanin and its derivatives as promising alternatives to conventional synthetic conductors. These materials, traditionally noted for their adhesive, antioxidant, biocompatible, and biodegradable properties, have barely been used as conductors due to their extremely low electrical activities. However, recent studies have demonstrated good conductive properties in melanin materials that promote electronic-ionic hybrid charge transfer, attributed to the formation of an extended conjugated backbone. This review examines the multifunctional properties of melanin materials, focusing on their chemical and electrochemical synthesis and their resulting structure-property-function relationship. The wide range of bioelectronic applications will also be presented to highlight their importance and potential to expand into new design concepts for high-performance electronic functional materials. The review concludes by addressing the current challenges in utilizing melanin for biodegradable bioelectronics, providing a perspective on future developments.

Magnetic Nanoparticles: A Comprehensive Review from Synthesis to Biomedical Frontiers

Nanotechnology has opened new doors of exploration, particularly in materials science and healthcare. Magnetic nanoparticles (MNP), the tiny magnets, because of their various properties, have the potential to bring about radical changes in the field of medicine. The distinctive surface chemistry, nontoxicity, biocompatibility, and, in particular, the inducible magnetic moment of magnetic materials has attracted a great deal of interest in morphological structures from a variety of scientific domains. This review presents a concise overview of MNPs and their crucial properties and synthesis routes. It also aims to highlight the continuous synthesis methods available for MNP production. In recent years, the use of computational methods for understanding the behavior of nanoparticles has been on the rise. Thus, we also discuss the numerical models developed to understand how magnetic nanoparticles can be used in magnetic hyperthermia and targeting the Circle of Wilis. With the increasing use of MNPs in biomedical applications, it becomes necessary to understand the mechanisms of toxicity, which are elucidated in this review. The review focuses on the biomedical applications of MNPs in drug delivery, theranostics, and MRI contrasting agents. We anticipate that this article will broaden the perspective on magnetic nanoparticles and help to understand their functionality and applicability better.

The Recent Applications of Magnetic Nanoparticles in Biomedical Fields

Magnetic nanoparticles (MNPs) have found extensive application in the biomedical domain due to their enhanced biocompatibility, minimal toxicity, and strong magnetic responsiveness. MNPs exhibit great potential as nanomaterials in various biomedical applications, including disease detection and cancer therapy. Typically, MNPs consist of a magnetic core surrounded by surface modification coatings, such as inorganic materials, organic molecules, and polymers, forming a nucleoshell structure that mitigates nanoparticle agglomeration and enhances targeting capabilities. Consequently, MNPs exhibit magnetic responsiveness in vivo for transportation and therapeutic effects, such as enhancing medical imaging resolution and localized heating at the site of injury. MNPs are utilized for specimen purification through targeted binding and magnetic separation in vitro, thereby optimizing efficiency and expediting the process. This review delves into the distinctive functional characteristics of MNPs as well as the diverse bioactive molecules employed in their surface coatings and their corresponding functionalities. Additionally, the advancement of MNPs in various applications is outlined. Additionally, we discuss the advancements of magnetic nanoparticles in medical imaging, disease treatment, and in vitro assays, and we anticipate the future development prospects and obstacles in this field. The objective is to furnish readers with a thorough comprehension of the recent practical utilization of MNPs in biomedical disciplines.

The Induction of Combined Hyperthermal Ablation Effect of Irreversible Electroporation with Polydopamine Nanoparticle-Coated Electrodes

Irreversible electroporation (IRE) is a prominent non-thermal ablation method widely employed in clinical settings for the focal ablation therapy of solid tumors. Utilizing high-voltage, short-duration electric pulses, IRE induces perforation defects in the cell membrane, leading to apoptotic cell death. Despite the promise of irreversible electroporation (IRE) in clinical applications, it faces challenges concerning the coverage of target tissues for ablation, particularly when compared to other thermal ablation therapies such as radiofrequency ablation, microwave ablation, and cryoablation. This study aims to investigate the induced hyperthermal effect of IRE by applying a polydopamine nanoparticle (Dopa NP) coating on the electrode. We hypothesize that the induced hyperthermal effect enhances the therapeutic efficacy of IRE for cancer ablation. First, we observed the hyperthermal effect of IRE using Dopa NP-coated electrodes in hydrogel phantom models and then moved to in vivo models. In particular, in in vivo animal studies, the IRE treatment of rabbit hepatic lobes with Dopa NP-coated electrodes exhibited a two-fold higher increase in temperature (ΔT) compared to non-coated electrodes. Through a comprehensive analysis, we found that IRE treatment with Dopa NP-coated electrodes displayed the typical histological signatures of hyperthermal ablation, including the disruption of the hepatic cord and lobular structure, as well as the infiltration of erythrocytes. These findings unequivocally highlight the combined efficacy of IRE with Dopa NPs for electroporation and the hyperthermal ablation of target cancer tissues.

Melanin/melanin-like nanoparticles: As a naturally active platform for imaging-guided disease therapy

The development of biocompatible and efficient nanoplatforms that combine diagnostic and therapeutic functions is of great importance for precise disease treatment. Melanin, an endogenous biopolymer present in living organisms, has attracted increasing attention as a versatile bioinspired functional platform owing to its unique physicochemical properties (e.g., high biocompatibility, strong chelation of metal ions, broadband light absorption, high drug binding properties) and inherent antioxidant, photoprotective, anti-inflammatory, and anti-tumor effects. In this review, the fundamental physicochemical properties and preparation methods of natural melanin and melanin-like nanoparticles were outlined. A systematical description of the recent progress of melanin and melanin-like nanoparticles in single, dual-, and tri-multimodal imaging-guided the visual administration and treatment of osteoarthritis, acute liver injury, acute kidney injury, acute lung injury, brain injury, periodontitis, iron overload, etc. Was then given. Finally, it concluded with a reasoned discussion of current challenges toward clinical translation and future striving directions. Therefore, this comprehensive review provides insight into the current status of melanin and melanin-like nanoparticles research and is expected to optimize the design of novel melanin-based therapeutic platforms and further clinical translation.

Poly(levodopa)-Functionalized Polysaccharide Hydrogel Enriched in Fe3O4 Particles for Multiple-Purpose Biomedical Applications

In recent years, there has been a significant increase in interest in the use of curdlan, a naturally derived polymer, for medical applications. However, it is relatively inactive, and additives increasing its biomedical potential are required; for example, antibacterial compounds, magnetic particles, or hemostatic agents. The stability of such complex constructs may be increased by additional functional networks, for instance, polycatecholamines. The article presents the production and characterization of functional hydrogels based on curdlan enriched with Fe₃O₄ nanoparticles (NPs) or Fe₃O₄-based heterostructures and poly(L-DOPA) (PLD). Some of the prepared modified hydrogels were nontoxic, relatively hemocompatible, and showed high antibacterial potential and the ability to convert energy with heat generation. Therefore, the proposed hydrogels may have potential applications in temperature-controlled regenerative processes as well as in oncology therapies as a matrix of increased functionality for multiple medical purposes. The presence of PLD in the curdlan hydrogel network reduced the release of the NPs but slightly increased the hydrogel's hemolytic properties. This should be taken into account during the selection of the final hydrogel application.

Polydopamine/IR820 nanoparticles as topical phototheranostics for inhibiting psoriasiform lesions through dual photothermal and photodynamic treatments

Dual photothermal and photodynamic therapy (PTT and PDT) is an attractive approach that generates a synergistic effect for inhibiting keratinocyte hyperproliferation in the treatment of psoriasis. Here, we developed phototheranostic nanocarriers capable of producing hyperthermia and reactive oxygen species (ROS) in response to near-infrared (NIR) illumination. To this end, IR820 with photothermal and photodynamic features was embedded in nano-sized polydopamine (PDA) acting as a PTT agent. A comprehensive characterization of the PDA/IR820 nanosystem was performed according to its morphology, size, zeta potential, UV absorbance, and heat generation. Its therapeutic efficacy was assessed by a keratinocyte-based study and using an imiquimod (IMQ)-stimulated psoriasiform murine model. PDA/IR820 nanoparticles were facilely internalized into keratinocytes and mainly resided in lysosomes. Upon irradiation with NIR light, ROS were generated inside the keratinocytes to cause a photodynamic effect. The live/dead cell assay and cytotoxicity assay demonstrated that PDA and IR820 acted as effective photoabsorbers to induce keratinocyte death. The highest cytotoxic effect was detected in the group of NIR-irradiated PDA/IR820 nanoparticles, which killed 52% of keratinocytes. The nanosystem acted through the caspase and poly ADP-ribose polymerase (PARP) pathways to induce keratinocyte apoptosis. In vitro and in vivo skin permeation indicated the selective accumulation of the topically applied PDA/IR820 nanoparticles within psoriasiform skin, suggesting their skin-targeting capability. The combination of PDA/IR820 nanoparticles and NIR irradiation increased the skin temperature by 11.7 °C. PTT/PDT eliminated psoriasiform plaques in mice by decreasing hyperplasia, inhibiting cytokine overexpression, and recovering the barrier function. The epidermal thickness of the IMQ-treated skin was reduced from 134 to 34 μm by the nanocarriers plus NIR. The IR820 nanoparticles were largely deposited on the inflamed areas of psoriasiform lesions for monitoring the severity of inflammation. The image-guided phototheranostic nanoparticles showed their potential for applications in psoriasis management via noninvasive topical administration.

Research Progress of Photothermal Nanomaterials in Multimodal Tumor Therapy

The aggressive growth of cancer cells brings extreme challenges to cancer therapy while triggering the exploration of the application of multimodal therapy methods. Multimodal tumor therapy based on photothermal nanomaterials is a new technology to realize tumor cell thermal ablation through near-infrared light irradiation with a specific wavelength, which has the advantages of high efficiency, less adverse reactions, and effective inhibition of tumor metastasis compared with traditional treatment methods such as surgical resection, chemotherapy, and radiotherapy. Photothermal nanomaterials have gained increasing interest due to their potential applications, remarkable properties, and advantages for tumor therapy. In this review, recent advances and the common applications of photothermal nanomaterials in multimodal tumor therapy are summarized, with a focus on the different types of photothermal nanomaterials and their application in multimodal tumor therapy. Moreover, the challenges and future applications have also been speculated.

Enhanced thermodynamic, pharmacokinetic and theranostic properties of polymeric micelles via hydrophobic core-clustering of superparamagnetic iron oxide nanoparticles

Background

Superparamagnetic iron oxide nanoparticles (SPIO) have been applied for decades to design theranostic polymeric micelles for targeted cancer therapy and diagnostic MR imaging. However, the effects of SPIO on the physicochemical, and biological properties of polymeric micelles have not yet been fully elucidated. Therefore, we investigated potential effect of SPIO on the physical and biological properties of theranostic polymeric micelles using representative cancer drug (doxorubicin; Doxo) and polymer carrier (i.e., poly (ethylene glycol)-co-poly(D,L-lactide), PEG-PLA).

Methods

SPIO were synthesized from Fe(acetyl acetonate)₃ in an aryl ether. SPIO and Doxo were loaded into the polymeric micelles by a solvent-evaporation method. We observed the effect of SPIO-clustering on drug loading, micelle size, thermodynamic stability, and theranostic property of PEG-PLA polymeric micelles. In addition, cellular uptake behaviors, pharmacokinetic and biodistribution study were performed.

Results

SPIO formed hydrophobic geometric cavity in the micelle core and significantly affected the integrity of micelles in terms of micelle size, Doxo loading, critical micelle concentration (CMC) and in vitro dissociation. In vivo pharmacokinetic studies also showed the enhanced Area Under Curve (AUC) and elongated the half-life of Doxo.

Conclusions

Clustered SPIO in micelles largely affects not only MR imaging properties but also biological and physical properties of polymeric micelles.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40824-022-00255-9.

Recent developments in mesoporous polydopamine-derived nanoplatforms for cancer theranostics

Polydopamine (PDA), which is derived from marine mussels, has excellent potential in early diagnosis of diseases and targeted drug delivery owing to its good biocompatibility, biodegradability, and photothermal conversion. However, when used as a solid nanoparticle, the application of traditional PDA is restricted because of the low drug-loading and encapsulation efficiencies of hydrophobic drugs. Nevertheless, the emergence of mesoporous materials broaden our horizon. Mesoporous polydopamine (MPDA) has the characteristics of a porous structure, simple preparation process, low cost, high specific surface area, high light-to-heat conversion efficiency, and excellent biocompatibility, and therefore has gained considerable interest. This review provides an overview of the preparation methods and the latest applications of MPDA-based nanodrug delivery systems (chemotherapy combined with radiotherapy, photothermal therapy combined with chemotherapy, photothermal therapy combined with immunotherapy, photothermal therapy combined with photodynamic/chemodynamic therapy, and cancer theranostics). This review is expected to shed light on the multi-strategy antitumor therapy applications of MPDA-based nanodrug delivery systems.

Photothermal treatment by PLGA-gold nanorod-isatin nanocomplexes under near-infrared irradiation for alleviating psoriasiform hyperproliferation

Psoriasis is a chronic autoimmune skin disorder that involves keratinocyte hyperproliferation and inflammatory cell recruitment. A strategy to mitigate psoriatic lesions is to induce keratinocyte apoptosis for proliferation suppression. Herein we designed a nanoformulation capable of treating psoriasis via hyperthermia-induced apoptosis in response to near-infrared (NIR) irradiation. To this end, gold nanorods (GNRs) and isatin, which is an anti-inflammatory agent for synergizing antipsoriatic activity, were loaded into a poly (lactic-co-glycolic acid) (PLGA) matrix to form the nanocomplexes. The physicochemical and photothermal properties of the nanocomplexes were determined in terms of size, surface charge, NIR-absorbing feature, isatin release, keratinocyte uptake, and cytotoxicity. The nanocomplexes showed a spherical shape with an average size of about 180 nm. The GNR-loaded nanoparticles can efficiently convert NIR light at 0.42 W/cm² into heat with an increased temperature of 10 °C. When combined with NIR exposure, the nanocomplexes were internalized into keratinocyte cytoplasm with an inhibition of keratinocyte viability to about 60%. Live/dead cell assay and flow cytometry confirmed that the nanocomplexes could serve as NIR-absorbers to specifically elicit keratinocyte apoptosis through caspase and poly ADP-ribose polymerase (PARP) pathways. The in vivo psoriasiform murine model indicated that the combined nanocomplexes and NIR inhibited epidermal hyperplasia and neutrophil infiltration. The overexpressed cytokines in the lesion could be recovered to normal baseline level after the photothermal management. The subcutaneous nanocomplexes remained in the skin for at least 5 days. The nanocomposites produced a negligible toxicity in the skin or liver of healthy mice. The photothermal nanosystems, as designed in this study, shed new light on the therapeutic approach against psoriasis.

Advances in Multiple Stimuli-Responsive Drug-Delivery Systems for Cancer Therapy

Nanomedicines afford unique advantages in therapeutic intervention against tumors. However, conventional nanomedicines have failed to achieve the desired effect against cancers because of the presence of complicated physiological fluids and the tumor microenvironment. Stimuli-responsive drug-delivery systems have emerged as potential tools for advanced treatment of cancers. Versatile nano-carriers co-triggered by multiple stimuli in different levels of organisms (eg, extracorporeal, tumor tissue, cell, subcellular organelles) have aroused widespread interest because they can overcome sequential physiological and pathological barriers to deliver diverse therapeutic “payloads” to the desired targets. Furthermore, multiple stimuli-responsive drug-delivery systems (MSR-DDSs) offer a good platform for co-delivery of agents and reversing multidrug resistance. This review affords a comprehensive overview on the “landscape” of MSR-DDSs against tumors, highlights the design strategies of MSR-DDSs in recent years, discusses the putative advantage of oncotherapy or the obstacles that so far have hindered the clinical translation of MSR-DDSs.