Hierarchical Micro-/Nanostructures from Human Hair for Biomedical Applications

Injectable and Degradable Zwitterionic Cryogels as Cancer Vaccine Platforms to Prevent Cancer Recurrence after Surgery

Cancer has become a highly prevalent disease and poses serious threats to human health. Conventional cancer treatments still face high risks of recurrence. Training the immune system to recognize and eliminate tumors via external stimulation, such as vaccines, emerges as a promising approach for cancer prevention and treatment. However, injectable vaccines may have limited immune activation, causing difficulties in maintaining long-term immune surveillance of tumorigenesis by tumor-specific cytotoxic T cells. Here, degradable zwitterionic cryogels were prepared using the cryogelation technique. The cryogenic preparation maintained the biological activities of tumor antigens and immune adjuvants loaded in the cryogels. The macroporous structure endowed the injectability of cryogels into the body via conventional syringes. In the presence of proteases, the cryogels degraded, allowing sustained release of antigens and adjuvants, ensuring continued dendritic cell (DC) recruitment and antigen presentation to maturing tumor-specific cytotoxic T cells. In vivo experiments demonstrated that the cryogel cancer vaccines elicited robust immune activation and effectively modulated tumor microenvironments. The combination with photothermal therapy significantly inhibited tumor growth, showing great potential for preventing postoperative recurrence. Additionally, the zwitterionic cryogels were biocompatible without obvious toxicities during degradation. The cryogels could serve as effective vaccine platforms to prevent cancer recurrence after surgery.

Direct cytosolic delivery of siRNA via cell membrane fusion using cholesterol-enriched exosomes

Efficient cytosolic delivery is a significant hurdle when using short interfering RNA (siRNA) in therapeutic applications. Here we show that cholesterol-rich exosomes are prone to entering cancer cells through membrane fusion, achieving direct cytosolic delivery of siRNA. Molecular dynamics simulations suggest that deformation and increased contact with the target cell membrane facilitate membrane fusion. In vitro we show that cholesterol-enriched milk-derived exosomes (MEs) achieve a significantly higher gene silencing effect of siRNA, inducing superior cancer cell apoptosis compared with the native and cholesterol-depleted MEs, as well as conventional transfection agents. When administered orally or intravenously to mice bearing orthotopic or subcutaneous tumours, the cholesterol-enriched MEs/siRNA exhibit antitumour activity superior to that of lipid nanoparticles. Collectively, by modulating the cholesterol content of exosome membranes to facilitate cell entry via membrane fusion, we provide a promising approach for siRNA-based gene therapy, paving the way for effective, safe and simple gene therapy strategies.

Photothermal Particle-Loaded Panax Notoginseng Polysaccharide Cryogels As Personalized Tumor Vaccines

Combination immunotherapy is being increasingly explored for cancer treatment, leading to various vector materials for the codelivery of immune agents and drugs. However, current tumor vaccines exhibit poor immunogenicity, severely compromising their therapeutic efficacy. Herein, an injectable hydrogel was developed based on dopamine (DA) and Panax notoginseng polysaccharide (PNPS) loaded with hair microparticles (HMPs) to enhance the immunogenicity of tumor vaccines. Photothermal effects of incorporated HMPs can trigger immunogenic cancer cell death and the release of abundant autologous tumor antigens, which are captured by catechol groups. Concomitant breakdown of PNPS recruits and activates dendritic cells (DCs). The macroporous structure of cryogels allows immune cell infiltration and interaction with antigens adsorbed on PNPS and DA cryogels (PD cryogels), thereby provoking potent cytotoxic T-cell responses. Hence, PD cryogels enabling cell infiltration and accelerated DC maturation may serve as a therapeutic vaccination platform against cancer.

Melanin Nanoparticle-Modified Probiotics for Targeted Synergistic Therapy of Ulcerative Colitis

Ulcerative colitis (UC) is a recurrent chronic mucosal inflammation disease whose most significant pathological characteristics are intestinal inflammation and damaged mucosal barrier induced by reactive oxygen/nitrogen species, abnormal immune microenvironment, and intestinal microecological imbalance. Oral probiotics are a living therapy for intestinal diseases, but their clinical application is hindered by poor bacterial biological activity and insufficient intestinal retention. Here, we developed a targeted oral formulation, functionalized probiotic Lf@MPB, with Lactobacillus fermentum (Lf) as the core and modified melanin nanoparticles (MNPs) on its surface through a click reaction of tricarboxyphenylboronic acid for synergistic therapy of UC. In vitro experiments showed that Lf@MPB not only possessed strong free radical scavenging ability, reduced cellular mitochondrial polarization, and inhibited apoptosis but also significantly enhanced the viability of Lf probiotics in simulated gastrointestinal fluid. Fluorescence imaging in vivo revealed the high accumulation of Lf@MPB at the site of intestinal inflammation in dextran sulfate sodium-induced UC mice. Moreover, in vivo results demonstrated that Lf@MPB effectively alleviated oxidative stress and inflammatory response and restored the intestinal barrier. In addition, 16S rRNA gene sequencing verified that Lf@MPB could increase the abundance and diversity of intestinal microbial communities and optimize microbial composition to inhibit the progression of UC. This work combines effective antioxidant and anti-inflammatory strategies with the oral administration of functionalized probiotics to provide a promising alternative for UC treatment.

Natural Extracts for Antibacterial Applications

Bacteria-induced epidemics and infectious diseases are seriously threatening the health of people around the world. In addition, antibiotic therapy has been inducing increasingly more serious bacterial resistance, which makes it urgent to develop new treatment strategies to combat bacteria, including multidrug-resistant bacteria. Natural extracts displaying antibacterial activity and good biocompatibility have attracted much attention due to greater concerns about the safety of synthetic chemicals and emerging drug resistance. These antibacterial components can be isolated and utilized as antimicrobials, as well as transformed, combined, or wrapped with other substances by using modern assistive technologies to fight bacteria synergistically. This review summarizes recent advances in natural extracts from three kinds of sources-plants, animals, and microorganisms-for antibacterial applications. This work discusses the corresponding antibacterial mechanisms and the future development of natural extracts in antibacterial fields.

Developing Safe Organohydrogel Sunscreens Using Polyelectrolyte-Betaine Surfactant Complexes

Oil-in-water emulsions are extensively used in skincare products due to their improved texture, stability, and effectiveness. There is limited success in developing effective delivery systems that can selectively target the active sunscreen ingredients onto the skin surface. Herein, an organohydrogel was prepared by physical cross-linking of an oil-in-water nanoemulsion with chitosan under neutral pH conditions. In the presence of a small quantity of coconut oil, lauramidopropyl betaine and glycerol were able to emulsify the active sunscreen ingredients into nanoscale droplets with enhanced ultraviolet light absorption. A facile pH-triggered interfacial cross-linking approach was applied to transform the nanoemulsion into an organohydrogel sunscreen. Furthermore, the organohydrogel sunscreen displayed encouraging characteristics including efficient UV-blocking capacity, resistance to water, simple removal, and minimal skin penetration. This facile approach provides an effective pathway for scaling up the organohydrogels, which are highly suitable for the safe application of sunscreen.

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.

Multifunctional zwitterionic microneedle dressings for accelerated healing of chronic infected wounds in diabetic rat models

Diabetic infected wounds are one of the major threats to public health but traditional wound dressings always have poor therapeutic efficacy influenced by the single treatment principle and limited penetration depth. Herein, we developed a novel kind of multifunctional degradable and removable zwitterionic microneedle dressings that could achieve multi-effective treatment of diabetic chronic wounds with a single dressing application. The substrates of microneedle dressings are composed of zwitterionic polymer polysulfobetaine methacrylate (PSBMA) and photothermal hair particles (HMPs), which can absorb wound exudate, form a barrier to the bacterial environment for the wound and exhibit an excellent photothermal bactericidal effect to promote wound healing. By loading zinc oxide nanoparticles (ZnO NPs) and asiaticoside in needle tips, drugs could diffuse in the wound area as the tips degrade to achieve highly effective antibacterial and anti-inflammatory effects and promote deep wound healing and tissue regeneration. The microneedles (MNs) were applied in diabetic rats with Staphylococcus aureus-infected wounds to demonstrate that the combination of drug and photothermal multi-treatment has accelerated tissue regeneration and collagen deposition and significantly promoted wound healing.

Hair Derived Microneedle Patches for Both Diabetic Foot Ulcer Prevention and Healing

The large amount of reactive oxygen species (ROS) produced by high glucose metabolism in diabetic patients not only induces inflammation but also damages blood vessels, finally resulting in low limb temperature, and the high glucose environment in diabetic patients also makes them susceptible to bacterial infection. Therefore, diabetic foot ulcer (DFU) usually presents as a nonhealing wound. To efficaciously prevent and treat DFU, we proposed a near-infrared (NIR) responsive microneedle (MN) patch hierarchical microparticle (HMP)-ZnO-MN-vascular endothelial growth factor and basic fibroblast growth factor (H-Z-MN-VEGF&bFGF), which could deliver drugs to the limbs painlessly, accurately, and controllably under NIR irradiation. Therein, the hair-derived HMPs exhibited the capacity of scavenging ROS, thereby preventing damage to the blood vessels. Meanwhile, zinc oxide (ZnO) nanoparticles endowed the MN patch with excellent antibacterial activity which could be further enhanced with the photothermal effect of HMPs under NIR irradiation. Moreover, vascular endothelial growth factor and basic fibroblast growth factor could promote the angiogenesis. A series of experiments proved that the MN patch exhibited broad-spectrum antibacterial and anti-inflammatory capacities. In vivo, it obviously increased the temperature of fingertips in diabetic rats as well as promoted collagen deposition and angiogenesis during wound healing. In conclusion, this therapeutic platform provides a promising method for the prevention and treatment of DFU.

Melanin nanoparticles alleviate sepsis-induced myocardial injury by suppressing ferroptosis and inflammation

Myocardial injury as one of the severe complications leads to the increasing morbidity and mortality in patients with sepsis. Recent studies reported that reactive oxygen species (ROS)-mediated ferroptosis plays a critical role in the development of heart diseases. Therefore, we hypothesized that anti-ferroptosis agent might be a novel potential therapeutic strategy for sepsis-induced cardiac injury. Herein, we demonstrated that a small biocompatible and MRI-visible melanin nanoparticles (MMPP) improves myocardial function by inhibiting ROS-related ferroptosis signaling pathway. In LPS-induced murine sepsis model, after a single dose intravenously injection of MMPP treatment, MMPP markedly alleviated the myocardial injury including cardiac function and heart structure disorder through suppressing iron-accumulation induced ferroptosis. In vitro, MMPP inhibited cardiomyocyte death by attenuating oxidative stress, inflammation and maintaining mitochondrial homeostasis. Collectively, our findings demonstrated that MMPP protected heart against sepsis-induced myocardial injury via inhibiting ferroptosis and inflammation, which might be a novel therapeutic approach in future.

A plant-derived natural photosynthetic system for improving cell anabolism

Insufficient intracellular anabolism is a crucial factor involved in many pathological processes in the body1,2. The anabolism of intracellular substances requires the consumption of sufficient intracellular energy and the production of reducing equivalents. ATP acts as an 'energy currency' for biological processes in cells3,4, and the reduced form of NADPH is a key electron donor that provides reducing power for anabolism5. Under pathological conditions, it is difficult to correct impaired anabolism and to increase insufficient levels of ATP and NADPH to optimum concentrations1,4,6-8. Here we develop an independent and controllable nanosized plant-derived photosynthetic system based on nanothylakoid units (NTUs). To enable cross-species applications, we use a specific mature cell membrane (the chondrocyte membrane (CM)) for camouflage encapsulation. As proof of concept, we demonstrate that these CM-NTUs enter chondrocytes through membrane fusion, avoid lysosome degradation and achieve rapid penetration. Moreover, the CM-NTUs increase intracellular ATP and NADPH levels in situ following exposure to light and improve anabolism in degenerated chondrocytes. They can also systemically correct energy imbalance and restore cellular metabolism to improve cartilage homeostasis and protect against pathological progression of osteoarthritis. Our therapeutic strategy for degenerative diseases is based on a natural photosynthetic system that can controllably enhance cell anabolism by independently providing key energy and metabolic carriers. This study also provides an enhanced understanding of the preparation and application of bioorganisms and composite biomaterials for the treatment of disease.

Cell membrane-coated human hair nanoparticles for precise disease therapies

Precision medicine is the ultimate goal for current disease therapies, including tumor and infection. The lack of specific targeted drugs for liver cancer and the lack of specific anti-infective drugs in the treatment of diabetic foot ulcer with infection (DFI) are the representative obstacles in those 2 major diseases currently plaguing human beings. Inventing natural biocompatible polymers derived from natural materials is one of the main development directions of current bio-medical materials. Though previous studies have demonstrated the potential application values of human black hair-derived nanoparticles (HNP) in cancer, methicillin-resistant Staphylococcus aureus (MRSA) infection, and thrombosis scenarios treatments, it still has not solved the problem of low local therapeutic concentration and general targeting ability. Here, we firstly modified the HNP with membrane encapsulations, which endowed these dual-pure natural bio-fabricated materials with better targeting ability at the disease sites with no reduction in photothermal therapy (PTT) effect. HNP coated by red blood cell membrane loaded with DSPE-PEG-cRGD peptide for the therapeutic application of liver cancer greatly prolonged in vivo circulation time and enhanced local targeting efficacy as well as low toxicity; HNP coated by the murine macrophage cell membrane (RAWM) for the DFIs treatment greatly promoted the adhesive ability of HNP on the bacteria and thereby improved the killing effect. Briefly, the appropriate cell membranes camouflaged HNP nanomedicine has the characteristics of excellent photothermal effect, an all-natural source with excellent biocompatibility and easy access, which is expected to have huge potential in both benign and malignant diseases.

Bioceramic Scaffolds with Antioxidative Functions for ROS Scavenging and Osteochondral Regeneration

Osteoarthritis (OA) is a degenerative disease that involves excess reactive oxygen species (ROS) and osteochondral defects. Although multiple approaches have been developed for osteochondral regeneration, how to balance the biochemical and physical microenvironment in OA remains a big challenge. In this study, a bioceramic scaffold by 3D printed akermanite (AKT) integrated with hair-derived antioxidative nanoparticles (HNPs)/microparticles (HMPs) for ROS scavenging and osteochondral regeneration has been developed. The prepared bioscaffold with multi-mimetic enzyme effects, which can scavenge a broad spectrum of free radicals in OA, can protect chondrocytes under the ROS microenvironment. Importantly, the bioscaffold can distinctly stimulate the proliferation and maturation of chondrocytes due to the stimulation of the glucose transporter pathway (GLUT) via HNPs/HMPs. Furthermore, it significantly accelerated osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). In vivo results showed that the bioscaffold can effectively enhance the osteochondral regeneration compared to the unmodified scaffold. The work shows that integration of antioxidant and mechanical properties via the bioscaffold is a promising strategy for osteochondral regeneration in OA treatment.

Natural Melanin/Alginate Hydrogels Achieve Cardiac Repair through ROS Scavenging and Macrophage Polarization

The efficacy of cardiac regenerative strategies for myocardial infarction (MI) treatment is greatly limited by the cardiac microenvironment. The combination of reactive oxygen species (ROS) scavenging to suppress the oxidative stress damage and macrophage polarization to regenerative M2 phenotype in the MI microenvironment can be desirable for MI treatment. Herein, melanin nanoparticles (MNPs)/alginate (Alg) hydrogels composed of two marine-derived natural biomaterials, MNPs obtained from cuttlefish ink and alginate extracted from ocean algae, are proposed. Taking advantage of the antioxidant property of MNPs and mechanical support from injectable alginate hydrogels, the MNPs/Alg hydrogel is explored for cardiac repair by regulating the MI microenvironment. The MNPs/Alg hydrogel is found to eliminate ROS against oxidative stress injury of cardiomyocytes. More interestingly, the macrophage polarization to regenerative M2 macrophages can be greatly promoted in the presence of MNPs/Alg hydrogel. An MI rat model is utilized to evaluate the feasibility of the as-prepared MNPs/Alg hydrogel for cardiac repair in vivo. The antioxidant, anti-inflammatory, and proangiogenesis effects of the hydrogel are investigated in detail. The present study opens up a new way to utilize natural biomaterials for MI treatment and allows to rerecognize the great value of natural biomaterials in cardiac repair.

Recent near-infrared light-activated nanomedicine toward precision cancer therapy

Light has been present throughout the history of mankind and even the universe. It is of great significance to human life, contributing to energy, agriculture, communication, and much more. In the biomedical field, light has been developed as a switch to control medical processes with minimal invasion and high spatiotemporal selectivity. During the past three years, near-infrared (NIR) light as long-wavelength light has been applied to more than 3000 achievements in biological applications due to its deep penetration depth and low phototoxicity. Remotely controlled cancer therapy usually involves the conversion of biologically inert NIR light. Thus, various materials, especially nanomaterials that can generate reactive oxygen species (ROS), ultraviolet (UV)/visual light, or thermal energy and so on under NIR illumination achieve great potential for the research of nanomedicine. Here, we offered an overview of recent advances in NIR light-activated nanomedicine for cancer therapeutic applications. NIR-light-conversion nanotechnologies for both directly triggering nanodrugs and smart drug delivery toward tumor therapy were discussed emphatically. The challenges and future trends of the use of NIR light in biomedical applications were also provided as a conclusion. We expect that this review will spark inspiration for biologists, materials scientists, pharmacologists, and chemists to fight against diseases and boost the future clinical-translational applications of NIR technology-based precision nanomedicine.

Injectable Hydrogel for Cu2+ Controlled Release and Potent Tumor Therapy

Disulfiram (DSF) is an important drug for the treatment and management of alcohol dependency. This drug has been approved by US-FDA, and its activity against the tumor is dependent on copper ion (Cu²⁺). However, the copper toxicity (caused via external copper) and its intrinsic anfractuous distribution in the human body have adversely suppressed the mechanism of DSF in in vivo. In this study, we aimed to design an injectable hydrogel, as CRC (Cu²⁺ release controller) for the effective treatment of tumors. The hydrogels of agarose have been used for wrapping of CuCl₂, and hierarchical microparticles (HMP) for the generation of CRC system. When the laser irradiations (808 nm) have been provided to the system, light energy is transferred into heat energy, which results in the hydrogel hydrolysis (reversible) due to the overheating effect. This is followed by a reaction with DSF (pre-injected) to suppress tumor progression. Hence, the CRC system brings innovative ideas for designing of a Cu²⁺ delivery system.

Cell primitive-based biomimetic functional materials for enhanced cancer therapy

Cell primitive-based functional materials that combine the advantages of natural substances and nanotechnology have emerged as attractive therapeutic agents for cancer therapy. Cell primitives are characterized by distinctive biological functions, such as long-term circulation, tumor specific targeting, immune modulation etc. Moreover, synthetic nanomaterials featuring unique physical/chemical properties have been widely used as effective drug delivery vehicles or anticancer agents to treat cancer. The combination of these two kinds of materials will catalyze the generation of innovative biomaterials with multiple functions, high biocompatibility and negligible immunogenicity for precise cancer therapy. In this review, we summarize the most recent advances in the development of cell primitive-based functional materials for cancer therapy. Different cell primitives, including bacteria, phages, cells, cell membranes, and other bioactive substances are introduced with their unique bioactive functions, and strategies in combining with synthetic materials, especially nanoparticulate systems, for the construction of function-enhanced biomaterials are also summarized. Furthermore, foreseeable challenges and future perspectives are also included for the future research direction in this field.

A zwitterionic polypeptide nanocomposite with unique NIR-I/II photoacoustic imaging for NIR-I/II cancer photothermal therapy

The second near infrared photoacoustic imaging (NIR-II PAI) and photothermal therapy (NIR-II PTT) have attracted wide interest in cancer theranostics because of maximum permission exposure (MPE), deep penetration, and lower scattering and background noise compared to NIR-I counterparts; however, it is imperative to develop biocompatible nanomaterials having NIR-II response. By utilizing multivalent Au-S coordination bonds, we constructed a zwitterionic polypeptide nanocomposite of PMC@AuNP with a suitable size of 48 ± 2 nm, which possessed a strong and broad absorbance at 650-1100 nm and an excellent photothermal conversion efficiency of 49.5%. In vitro biological studies demonstrated that NIR-II PTT within MPE was more effective than NIR-I PTT beyond MPE. Along with X-ray computed tomography and photothermal imaging functions, PMC@AuNP in vivo presented unique NIR-I/II PAI with 2.6-5.9 times signal enhancement compared to the contrast. By single dose and NIR-II irradiation (1064 nm, 1 W cm-2, 10 min), NIR-II PTT within MPE completely eradicated MCF-7 tumors without tissue damage and tumor recurrence within 24 days, inducing a better antitumor efficacy than NIR-I PTT beyond MPE. Importantly, this study provides an innovative method for the fabrication of biocompatible zwitterionic polypeptide nanocomposites with unique NIR-I/II PAI and NIR-II PTT attributes, thus holding great potential for precise cancer theranostics and further clinical transitions.

Human hair derived uPA loaded capsules with dual near-infrared (I and II biowindows) laser responsive capabilities for multi-effective thrombolysis therapy

Problems such as massive hemorrhage caused by uncontrolled drug dosage are the main significant obstacles in clinical thrombolytic therapy, which are prominently due to the lack of targeting and controlled release ability of efficient thrombolytic drug systems. In recent years, our team demonstrated that the photothermal effect can facilitate the thrombolytic effect of urokinase plasminogen activator (uPA). However, conventional photothermal agents are relatively expensive or contain heavy metals. If drug delivery systems with low toxicity, minimized heavy metal elements and easy accessibility (preferably provided by human self) can be developed, they will be of value in the future related applications. Herein, uPA-loaded human black hair derived nanoparticles with gelatin capsules (uPA@HBHNP@GNCs) were applied for the first time as a thrombolytic system. Upon irradiation by near-infrared I window (NIR-I) laser or II window (NIR-II) laser, the photothermal effect of HBHNP was triggered to promote the melting of the gelatin encapsulated around the outer layer, thereby realizing the targeted release of uPA. The in vitro and in vivo experiments demonstrated that the deep response to NIR (especially II window) of this system exhibited a satisfactory thrombolytic effect with ideal biosafety. Briefly, the proposed hair derived drug delivery system has the characteristics of human source, low cost, minimum heavy metal components, deep response to NIR (II window) laser, and good biocompatibility, which is expected to be expanded to the treatment for some diseases, even in deep tissue areas.

Bioinspired liquid gating membrane-based catheter with anticoagulation and positionally drug release properties

Catheters are indispensable medical devices that are extensively used in daily medical treatment. However, existing catheter materials continue to encounter many problems, such as thrombosis, single functionality, and inadaptability to environmental changes. Inspired by blood vessels, we develop a self-adaptive liquid gating membrane-based catheter with anticoagulation and positionally drug release properties. Our multifunctional liquid gating membrane-based catheter significantly attenuates blood clot formation and can be used as a general catheter design strategy to offer various drugs positionally releasing applications to comprehensively enhance the safety, functionality, and performance of medical catheters' materials.

Vascular disrupting agent induced aggregation of gold nanoparticles for photothermally enhanced tumor vascular disruption

Although vascular disrupting agents (VDAs) have been extensively implemented in current clinical tumor therapy, the notable adverse events caused by long-term dosing severely limit the therapeutic efficacy. To improve this therapy, we report a strategy for VDA-induced aggregation of gold nanoparticles to further destroy tumor vascular by photothermal effect. This strategy could effectively disrupt tumor vascular and cut off the nutrition supply after just one treatment. In the murine tumor model, this strategy results in notable tumor growth inhibition and gives rise to a 92.7% suppression of tumor growth. Besides, enhanced vascular damage could also prevent cancer cells from distant metastasis. Moreover, compared with clinical therapies, this strategy still exhibits preferable tumor suppression and metastasis inhibition ability. These results indicate that this strategy has great potential in tumor treatment and could effectively enhance tumor vascular damage and avoid the side effects caused by frequent administration.

Nanoparticles from Ancient Ink Endowing a Green and Effective Strategy for Cancer Photothermal Therapy in the Second Near-Infrared Window

Photothermal therapy (PTT) in the second near-infrared window (NIR-II, 1000-1350 nm) has presented great superiority in cancer treatment recently. However, it is generally limited to a few photothermal agents and most of them often suffer from intricate design and complicated synthesis. Herein, by subtly extracting nanoparticles from ancient ink (AINPs), a versatile AINP dispersion with definite ingredients, good biosafety, and excellent photothermal effect in the NIR-II window was obtained. In vivo trials demonstrated that the obtained AINP dispersion provides a promising alternative for tumor sentinel lymph node (SLN) mapping. Besides, under the guidance of photoacoustic imaging, the metastatic SLNs could be accurately eliminated by NIR-II laser irradiation. The preliminary biosafety of AINP dispersion has also been systematically confirmed. Therefore, we believe this work would provide a green and effective strategy for PTT of tumor in the NIR-II window.

Enzyme Mimicking Based on the Natural Melanin Particles from Human Hair

Natural enzymes are mainly composed by the protein part and metallic cofactor part, both of which work cooperatively to achieve high catalytic activity. Here, natural melanin particles (NMPs) were extracted from human hair and further bound with metal ions to mimic natural enzymes. The different metal-bound NMPs (M-NMPs) exhibited different enzyme-like activities with great promise in diverse biomedical applications. It was found that Fe-bound NMPs (Fe-NMPs) showed outstanding peroxidase (POD)-like activity that possessed potential in antibacterial applications, and Mn-bound NMPs (Mn-NMPs) displayed catalase (CAT)-like activity with a remarkable radiotherapy sensitization effect in cancer therapy. Besides, Cu-bound NMPs (Cu-NMPs) could serve as combined POD, superoxide dismutase (SOD), and CAT alternatives, which exhibited prominent reactive oxygen species (ROS) scavenging ability, revealing great potential in anti-inflammation. The versatile enzyme-like activities of M-NMPs derived from hair might give extensive perspective for designing biomedical materials and provide a promising tool in solving biomedical problems.

Lysozyme-Assisted Photothermal Eradication of Methicillin-Resistant Staphylococcus aureus Infection and Accelerated Tissue Repair with Natural Melanosome Nanostructures

Patients often face the challenge of antibiotic-resistant bacterial infections and lengthy tissue reconstruction after surgery. Herein, human hair-melanosome derivatives (HHMs), comprising keratins and melanins, are developed using a simple "low-temperature alkali heat" method for potentially personalized therapy. The mulberry-shaped HHMs have an average width of ∼270 nm and an average length of ∼700 nm, and the negatively charged HHMs can absorb positively charged Lysozyme (Lyso) to form the HHMs-Lyso composites through electrostatic interaction. These naturally derived biodegradable nanostructures act as exogenous killers to eliminate methicillin-resistant Staphylococcus aureus (MRSA) infection with a high antibacterial efficacy (97.19 ± 2.39%) by synergistic action of photothermy and "Lyso-assisted anti-infection" in vivo. Additionally, HHMs also serve as endogenous regulators of collagen alpha chain proteins through the "protein digestion and absorption" signaling pathway to promote tissue reconstruction, which was confirmed by quantitative proteomic analysis in vivo. Notably, the 13 upregulated collagen alpha chain proteins in the extracellular matrix (ECM) after HHMs treatment demonstrated that keratin from HHMs in collagen-dependent regulatory processes serves as a notable contributor to augmented wound closure. The current paradigm of natural material-tissue interaction regulates the cell-ECM interaction by targeting cell signaling pathways to accelerate tissue repair. This work may provide insight into the protein-level pathways and the potential mechanisms involved in tissue repair.

Zinc-doped Prussian blue enhances photothermal clearance of Staphylococcus aureus and promotes tissue repair in infected wounds

The application of photothermal therapy to treat bacterial infections remains a challenge, as the high temperatures required for bacterial elimination can damage healthy tissues. Here, we develop an exogenous antibacterial agent consisting of zinc-doped Prussian blue (ZnPB) that kills methicillin-resistant Staphylococcus aureus in vitro and in a rat model of cutaneous wound infection. Local heat triggered by the photothermal effect accelerates the release and penetration of ions into the bacteria, resulting in alteration of intracellular metabolic pathways and bacterial killing without systemic toxicity. ZnPB treatment leads to the upregulation of genes involved in tissue remodeling, promotes collagen deposition and enhances wound repair. The efficient photothermal conversion of ZnPB allows the use of relatively few doses and low laser flux, making the platform a potential alternative to current antibiotic therapies against bacterial wound infections.

Here, the authors apply transition metal doping in combination with phototermal therapy to treat Staphylococcus aureus-infected wounds, and show that release of ions by local heat enhances bacteria clearance and promotes tissue repair in a rat model of MRSA-infected wounds

Nanoparticles from Cuttlefish Ink Inhibit Tumor Growth by Synergizing Immunotherapy and Photothermal Therapy

Natural nanoparticles have been extensively studied due to their diverse properties and easy accessibility. Here, the nanoparticles extracted from cuttlefish ink (CINPs) with significant antitumor efficacy are explored. These CINPs, with spherical morphology, good dispersibility, and biocompatibility, are rich in melanin and contain a variety of amino acids and monosaccharides. Through the activation of mitogen-activated protein kinase (MAPK) signaling pathway, CINPs can efficiently reprogram tumor-associated macrophages (TAMs) from immune-suppressive M2-like phenotype to antitumor M1-like phenotype. Besides, under near-infrared (NIR) irradiation, CINPs exhibit high photothermal effect and tumor cell killing ability, which make them a potential candidate in photothermal therapy (PTT) of tumor. In vivo, CINPs can increase the proportion of M1 macrophages and foster the recruitment of cytotoxic T lymphocytes (CTLs) to tumors, leading to reduced primary tumor growth and lung metastasis. In combination with their photothermal effect, which can induce tumor-specific antigens release, CINPs could almost completely inhibit tumor growth accompanied by more active immune responses. Collectively, these CINPs described here can provide both tumor immunotherapy and PTT, implying that CINPs are promising for tumor treatment.

Proliferation of Cells with Severe Nuclear Deformation on a Micropillar Array

Cellular responses on a topographic surface are fundamental topics about interfaces and biology. Herein, a poly(lactide- co-glycolide) (PLGA) micropillar array was prepared and found to trigger significant self-deformation of cell nuclei. The time-dependent cell viability and thus cell proliferation was investigated. Despite significant nuclear deformation, all of the examined cell types (Hela, HepG2, MC3T3-E1, and NIH3T3) could survive and proliferate on the micropillar array yet exhibited different proliferation abilities. Compared to the corresponding groups on the smooth surface, the cell proliferation abilities on the micropillar array were decreased for Hela and MC3T3-E1 cells and did not change significantly for HepG2 and NIH3T3 cells. We also found that whether the proliferation ability changed was related to whether the nuclear sizes decreased in the micropillar array, and thus the size deformation of cell nuclei should, besides shape deformation, be taken into consideration in studies of cells on topological surfaces.

Multidrug resistant tumors-aimed theranostics on the basis of strong electrostatic attraction between resistant cells and nanomaterials

The gene expression of resistant cells usually raises the negative potential of cell membranes. Utilizing the strong electrostatic attraction of resistant cells with nanomaterials, multidrug resistance tumors-aimed theranostics is demonstrated.

Recent advances in nanomaterials for enhanced photothermal therapy of tumors

Nowadays, photothermal therapy (PTT) utilizing photothermal conversion agents (PTAs) to generate sufficient heat under near-infrared (NIR) light irradiation for tumor ablation has attracted extensive research attention. Despite the great advancement, the therapeutic efficacy of PTT in tumor treatment is still compromised by several obstacles, such as low photothermal conversion efficiency, poor stability of PTAs, inadequate tumor accumulation and cellular uptake, and thermal-resistance of tumors, as well as tumor recurrence and metastasis. In this review, we highlight recent advances in nanomaterials that focus on overcoming the above obstacles and thus enhancing the therapeutic outcome of PTT. PTAs with improved photothermal performance and modification strategies for efficient PTT are summarized, which are further classified into three main types, utilizing activatable PTAs, improving the local concentration of PTAs, and overcoming intrinsic drawbacks of PTT (e.g., heat shock responses). Furthermore, the limitations and challenges of nanomaterials for enhanced PTT are also discussed.

In situ growth of Au nanoparticles on natural melanin as biocompatible and multifunctional nanoagent for efficient tumor theranostics

Natural melanin has been demonstrated to be a biocompatible and efficient nanoagent for the photothermal ablation of tumors, but their practical applications are limited due to their lack of typical imaging functions (CT, MRI, etc.). Thus, to achieve multifunctional melanin-based nanoagents for imaging-guided therapy, for the first time, herein, we report the in situ growth of Au nanoparticles on natural melanin as a model through a simple and safe method. The as-synthesized samples are composed of melanin nanoparticles (diameter: ∼120 nm) whose surface are decorated by small Au nanoparticles with an adjustable size ranging from ∼10 to ∼40 nm. These Au-decorated melanin (Au-M) nanocomposites exhibit satisfactory near infrared (NIR) photoabsorption and high photothermal conversion efficiency of 42.3%. Furthermore, the Au-M nanocomposites have a high X-ray attenuation coefficient and exhibit excellent biocompatibility. When the Au-M solutions were injected into the tumor of a mouse, the tumor could be detected by X-ray computed tomography (CT), photoacoustic (PA) and thermal imaging, and then be thermally ablated under the illumination of an 808 nm laser. Therefore, these Au-M nanocomposites have great potential as a novel multifunctional and biocompatible nanoagent for imaging-guided photothermal tumor ablation.

A Simply Modified Lymphocyte for Systematic Cancer Therapy

Cytotherapy has received considerable attention in the field of cancer therapy, and various chemical or genetic methods have been applied to remold natural cells for improved therapeutic outcome of cytotherapy. A simple method to modify lymphocytes for cancer treatment by using a clinically used molecule, δ-aminolevulinic acid (δ-ALA), is reported here. After incubation with this molecule, tumor-targeted lymphocytes spontaneously synthesize anti-neoplastic drug protoporphyrin X (PpIX), and specifically accumulate in cancer tissue. Under periodic 630 nm laser irradiation, lymphocytes generate vesicle-like apoptotic body (Ab) containing the above-produced PpIX, and the facilitated delivery of PpIX from Ab makes an excellent therapeutic effect for Ras-mutated cancer cells under a second irradiation. Importantly, a microfluidic device is further fabricated to simplify cell sorting and drug synthesis with a one-step operation, which could promote generalization of this strategy. In vitro and in vivo studies confirm the success of such an easy-operated and global-regulated strategy for cancer therapy.