Keratin Nanoparticles Research Articles

Synthesis of Keratin Nanoparticles Extracted from Human Hair through Hydrolysis with Concentrated Sulfuric Acid: Characterization and Cytotoxicity.

Human hair, composed primarily of keratin, represents a sustainable waste material suitable for various applications. Synthesizing keratin nanoparticles (KNPs) from human hair for biomedical uses is particularly attractive due to their biocompatibility. In this study, keratin was extracted from human hair using concentrated sulfuric acid as the hydrolysis agent for the first time. This process yielded KNPs in both the supernatant (KNPs-S) and precipitate (KNPs-P) phases. Characterization involved scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Zeta potential analysis, X-ray diffraction (XRD), and thermogravimetric analysis (TG). KNPs-S and KNPs-P exhibited average diameters of 72 ± 5 nm and 27 ± 5 nm, respectively. The hydrolysis process induced a structural rearrangement favoring β-sheet structures over α-helices in the KNPs. These nanoparticles demonstrated negative Zeta potentials across the pH spectrum. KNPs-S showed higher cytotoxicity (CC50 = 176.67 µg/mL) and hemolytic activity, likely due to their smaller size compared to KNPs-P (CC50 = 246.21 µg/mL), particularly at concentrations of 500 and 1000 µg/mL. In contrast, KNPs-P did not exhibit hemolytic activity within the tested concentration range of 32.5 to 1000 µg/mL. Both KNPs demonstrated cytocompatibility with fibroblast cells in a dose-dependent manner. Compared to other methods reported in the literature and despite requiring careful washing and neutralization steps, sulfuric acid hydrolysis proved effective, rapid, and feasible for producing cytocompatible KNPs (biomaterials) in single-step synthesis.

Bisphosphonates activated keratin assembled nanoparticle targeting bone fracture for enhanced immunomodulatory and osteoinductivity

Bone fractures pose significant clinical challenges and require innovative solutions for effective treatment and rapid recovery. Nanoscale protein-based materials are prominent in biotechnology and biomedicine, demonstrating versatility in biological processes and drug delivery. Herein, we designed and fabricated self-assembled keratin nanoparticles via a bisphosphonate (BP)-activated conformation-conservative assembly process. We determined the structural properties of the nanoparticles and explored the immunomodulatory and osteoinductivity functions retained from keratin. In addition, the keratin-BP nanoparticles could repair bone fractures. This study on multifunctional self-assembled protein-drug nanoparticles provides useful baseline data for exploring novel therapeutic options for acute bone fracture and other diseases.

Rational design of keratin nanoparticles utilizing diverse hair protein fractions for controlled drug release

BackgroundHair keratin exhibits potential as a nanocarrier material owing to its biocompatibility, biodegradability, and adaptability. However, conventional extraction methods yield mixtures of KIFs and KAPs. While prior research has delved into keratin nanoparticles, none have specifically investigated those derived from distinct keratin subgroups. MethodsTo address this gap, we assessed the particle size, zeta potential, secondary structure, and drug release properties of spray-dried keratin nanoparticles generated from diverse KAPs/KIFs mixtures. Significant FindingsOur findings reveal that KAPs/KIFs ratios directly impact keratin nanoparticles’ protein structures and properties. When a higher proportion of KAPs is involved, there is a greater repulsive force between particles, reducing their tendency to aggregate. Conversely, increased KIFs content results in smaller particles and reduced electrostatic repulsion, potentially enhancing Theophylline release. Therefore, fine-tuning drug release behavior by adjusting KAPs and KIFs ratios while considering environmental pH values is critical to address aggregation problems while maximizing drug loading and encapsulation efficiency. These results underscore the importance of controlled keratin composition for developing reliable, keratin-based biomaterials tailored for diverse biomedical applications.

Microfluidic manufacturing of tioconazole loaded keratin nanocarriers: Development and optimization by design of experiments

Fungal infections of the skin, nails, and hair are a common health concern affecting a significant proportion of the population worldwide. The current treatment options include topical and systematic agents which have low permeability and prolonged treatment period, respectively. Consequently, there is a growing need for a permeable, effective, and safe treatment. Keratin nanoparticles are a promising nanoformulation that can improve antifungal agent penetration, providing sustainable targeted drug delivery. In this study, keratin nanoparticles were prepared using a custom-made 3D-printed microfluidic chip and the manufacturing process was optimized using the design of experiments (DoE) approach. The total flow rate (TFR), flow rate ratio (FRR), and keratin concentration were found to be the most influential factors of the size and polydispersity index (PDI) of the nanoparticles. The crosslinking procedure by means of tannic acid as safe and biocompatible compound was also optimized. Keratin nanoparticles loaded with a different amount of tioconazole showed a size lower than 200 nm, a PDI lower than 0.2 and an encapsulation efficiency of 91 ± 1.9 %. Due to their sustained drug release, the formulations showed acceptable in vitro biocompatibility. Furthermore, a significant inhibitory effect compared to the free drug against Microsporum canis.

A State-of-the-art Review on Keratin Biomaterial as Eminent Nanocarriers for Drug Delivery Applications

Abstract: The utilization of biomaterials in the human body was first practiced several years ago to restore normal functional activities by replacing the impaired organs with bio-inspired materials without devastating the cells and tissues. Today, many advanced technologies are reported to be worthwhile to effectively prepare different categories of biomaterials with amplified properties and characteristics for therapeutic applications. When considering the prosperous aspects of biomaterials, keratin has proved to be a fascinating material and has allured many researchers in various novel scientific studies, especially in drug delivery systems. Keratin is a naturally derived fibrous protein with cysteine, proline, serine, and glycine as the main amino acid constituents and has been found to have remarkable properties. Although keratin exhibits excellence and loss of distinction, it is utilized effectively in drug delivery for treating various diseases. Certainly, keratin nanoparticles (KNPs) showed remarkable features, such as optimistic surface area, good encapsulation efficiency, and controlled release of drugs. However, there is a need for more research to know about the cell interaction with keratin nanoparticles in novel drug delivery management. Indeed, certain biological and mechanical factors in alpha and beta keratins are still ambiguous, and higher attentiveness is required. The major purpose of this review is to assess the prospective utility and outstanding features of keratin nanoparticles in drug delivery systems. Keratin types, source of extraction, and properties are reviewed in this article. The characteristics and development of KNP are highlighted. Furthermore, the importance of nanoparticles in drug delivery, drug release mechanisms, challenges, and the need for future research are discussed.

Functionalization of keratin nanoparticles by their internal modifications

Functionalization of keratin nanoparticles by their internal modifications

Injectable oxidized alginate/carboxylmethyl chitosan hydrogels functionalized with nanoparticles for wound repair

Owing to its simple properties, the application of injectable hydrogel in wound repair is limited. Therefore, the multi-functionalization of injectable hydrogel to improve the therapeutic effect is imperative. Here, keratin nanoparticles (Ker NPs) with facilitating epithelization capability and nanosized-EGCG covered with Ag nanoparticles (AE NPs) with radicals scavenging capability were used to functionalize injectable oxidized alginate/carboxylmethyl chitosan hydrogel (KA hydrogel). The radical scavenging experiments proved the anti-oxidative capacity of AE NPs. Rheological test exhibited that the gelation time and storage modulus of KA hydrogel were about 216 s and 403 Pa. Additionally, wound healing experiment in vivo showed that KA hydrogel could accelerated wound healing, especially in the early stage, and improved the thickness of renascent epidermis by 21 %. In this work, Ker NPs and AE NPs functionalization endowed injectable hydrogels with the capabilities of scavenging radicals and facilitating epithelization, which is promising for the applications in wound repair.

Two Beats One: Osteosarcoma Therapy with Light-Activated and Chemo-Releasing Keratin Nanoformulation in a Preclinical Mouse Model

Osteosarcoma treatment is moving towards more effective combination therapies. Nevertheless, these approaches present distinctive challenges that can complicate the clinical translation, such as increased toxicity and multi-drug resistance. Drug co-encapsulation within a nanoparticle formulation can overcome these challenges and improve the therapeutic index. We previously synthetized keratin nanoparticles functionalized with Chlorin-e6 (Ce6) and paclitaxel (PTX) to combine photo (PDT) and chemotherapy (PTX) regimens, and the inhibition of osteosarcoma cells growth in vitro was demonstrated. In the current study, we generated an orthotopic osteosarcoma murine model for the preclinical evaluation of our combination therapy. To achieve maximum reproducibility, we systematically established key parameters, such as the number of cells to generate the tumor, the nanoparticles dose, the design of the light-delivery device, the treatment schedule, and the irradiation settings. A 60% engrafting rate was obtained using 10 million OS cells inoculated intratibial, with the tumor model recapitulating the histological hallmarks of the human counterpart. By scheduling the treatment as two cycles of injections, a 32% tumor reduction was obtained with PTX mono-therapy and a 78% reduction with the combined PTX-PDT therapy. Our findings provide the in vivo proof of concept for the subsequent clinical development of a combination therapy to fight osteosarcoma.

Self-assembled uniform keratin nanoparticles as building blocks for nanofibrils and nanolayers derived from industrial feather waste

Chicken slaughterhouses can produce extensive waste, mainly feathers, that needs to be managed properly to prevent environmental pollution. Low cost, biodegradability, low immunogenicity, and colloidal stability of recycled feather keratin makes it attractive to produce protein-based nanomaterials, which is the objective of this study. Based on feather keratin's inherent ability to self-aggregate, we hypothesize that it can be used to form small nanoparticles to create nanostructures in physiological media for potential medical purposes. Here, urea and 2-mercaptoethanol (2 ME) were used to solubilize feather keratin without damaging its primary structure. Fluorescence, Fourier transform infrared (FTIR), and circular dichroism (CD) spectroscopies revealed that, after removing urea and 2 ME by dialysis, keratin molecules were able to form new intra-molecular disulfide and hydrogen bonds, along with hydrophobic interactions to regain their three-dimensional conformation. They further self-aggregated into extremely small uniform 13.33 nm diameter nanoparticles, measured by field emission scanning electron microscopy (FESEM), with 22.83 nm hydrodynamic diameter, measured by dynamic light scattering (DLS). The FTIR and CD spectroscopy showed that the beta-sheet content of the keratin molecules increased after nanoparticle formation, and the Congo Red test indicated that they were partially amyloid in nature. The nanoparticles had a high tendency to establish interparticle bonds, leading to new arrangements in the form of nanofibrils, nanolayers, and larger nanoparticles. In a novel approach, the type of buffer, incubation time, temperature, pH, and concentration of keratin molecules were adjusted to control the formation of one-, two-, and three-dimensional nanostructures. The self-assembly behavior of small nanoparticles under non-degradative solubilization and controlled pH, temperature, and concentration, was utilized, for the first time, to generate nano-architected structures with predictable characteristics. The results provide a platform for the development of new biomedical keratin nanomaterials/nanocomposites on a large scale.

Rod-shaped keratin nanoparticles extracted from human hair by acid hydrolysis as photothermally triggered berberine delivery system

Human hair can be a sustainable keratin source to prepare cytocompatible drug nanocarriers. A simple and effective methodology to create rod-like keratin nanoparticles (KNPs) using acidic hydrolysis was reported in this work. The extracted KNPs were characterized by infrared spectroscopy (FTIR), X-Ray diffraction (XRD), thermal analysis (TG and DSC), Zeta potential measurements, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The KNPs presented an amorphous structure with a smaller average size and higher aspect ratio than KNPs created from previously reported alkaline methods. Furthermore, cell viability assays confirmed that the extracted KNPs are cytocompatible toward adipose mesenchymal stem cells (ADSCs) and healthy cells of the African green monkey (VERO cells). The material was evaluated as berberine (BERB) nanocarrier, a drug with anticancer activity. The BERB was associated with KNPs by adsorption. The rod-shaped KNPs presented a type II adsorption profile toward BERB, adsorbing approximately 168.05 ± 1.44 mg/g. BERB is a cationic species capable of interacting with negatively charged KNPs (Zeta potential equal to −33.8 mV at pH 8.0). After BERB adsorption, the KNPs/BERB Zeta potential is reduced to −10.14 mV (pH 8.0). The KNPs exhibited strong photothermal properties, which improved and enhanced the BERB desorption. The photothermal KNPs responsiveness promoted a sustained BERB release. The KNPs/BERB shows cytotoxity against colon adenocarcinoma cells (HT-29 cells). Therefore, the extracted rod-shaped KNPs can be alternative nanocarriers for BERB delivery.

Keratin-Based Nanoparticles as Drug Delivery Carriers

Keratin is a structural protein of mammalian tissues and birds, representing the principal constituent of hair, nails, skin, wool, hooves, horns, beaks, and feathers, and playing an essential role in protecting the body from external harassment. Due to its intrinsic features such as biocompatibility, biodegradability, responsiveness to specific biological environment, and physical–chemical properties, keratin has been extensively explored in the production of nanocarriers of active principles for different biomedical applications. In the present review paper, we aimed to give a literature overview of keratin-based nanoparticles produced starting from human hair, wool, and chicken feathers. Along with the chemical and structural description of keratin nanoparticles, selected in vitro and in vivo biological data are also discussed to provide a more comprehensive framework of possible fields of application of this protein. Despite the considerable number of papers describing the production and use of keratin nanoparticles as carries of anticancer and antimicrobial drugs or as hemostatic and wound healing materials, still, efforts are needed to implement keratin nanoparticles towards their clinical application.

Developing exquisite collagen fibrillar assemblies in the presence of keratin nanoparticles for improved cellular affinity

Recently, the collagen-keratin (CK) composites have received much attention for the purpose of biomedical applications due to the intrinsic biocompatibility and biodegradability of these two proteins. However, few studies have reported the CK composites developed by the self-assembly approach and the influence of the keratin on the collagen self-assembly in vitro was still unknown. In this study, the keratin nanoparticles (KNPs) were successfully prepared by the reduction method, and we focused on investigating the effect of the varying concentrations of KNPs on the mechanism of the fibrillogenesis process of collagen. The intermolecular interaction between the two proteins revealed by the ultraviolet spectroscopy, Fourier transform-infrared (FT-IR) spectroscopy and circular dichromatic (CD) spectroscopy showed that KNPs would interact with the collagen, and keratin significantly influenced the hydrogen bonding interaction existed in collagen molecules. The SEM images exhibited the formation of exquisite fibrillar networks after incorporating the KNPs into collagen, and it was conspicuous that the KNPs could uniformly distribute on the surface of collagen fibrils via electrostatic interaction, for both of the two proteins possessed many charged moieties. In addition, the AFM images confirmed the presence of the characteristic D-periodicity of collagen fibrils, indicating that the introduction of KNPs did not disrupt the self-assembly nature of the native collagen. The cell adhesion, proliferation and migration experiments on the CK fibrils were also performed in this study. The results demonstrated that the CK composites showed a better cellular affinity compared with the collagen, thus it might be a promising candidate for the biomedical applications.

Keratin nanoparticles and photodynamic therapy enhance the anticancer stem cells activity of salinomycin

The high rates of aggressiveness, drug resistance and relapse of breast cancer (BC) are mainly attributed to the inability of conventional therapies to equally eradicate bulk differentiated cells and cancer stem cells (CSCs). To improve the effectiveness of BC treatments, we report the in-water synthesis of novel keratin-based nanoformulations, loaded with the CSC-specific drug salinomycin (SAL), the photosensitizer chlorin e6 (Ce6) and vitamin E acetate (SAL/Ce6@kVEs), which combine the capability of releasing SAL with the production of singlet oxygen upon light irradiation. In vitro experiments on BC cell lines and CSC-enriched mammospheres exposed to single or combined therapies showed that SAL/Ce6@kVEs determine synergistic cell killing, limit their self-renewal capacity and decrease the stemness potential by eradication of CSCs. In vivo experiments on zebrafish embryos confirmed the capacity of SAL nanoformulations to interfere with the Wnt/β-catenin signaling pathway, which is dysregulated in BC, thus identifying a target for further translation into pre-clinical models.

Physical and biological synthesis of GNPs and keratin nanoparticles from chicken’s feather and applications

In this paper, we aim to synthesize keratin nanoparticles from chicken’s feather. Crude keratin was extracted by chemical method. We obtained results for keratin nanoparticles using glutaraldehyde as a cross-linking agent. In this study, gold nanoparticles (GNps prepared by way Laser Ablation) with keratin nanoparticles for the production of antibacterial materials. NPs samples were characterized using a Transmission Electron Microscope (TEM). The absorption spectra were measure by UV-Visible, double beam spectrophotometer. Three types of pathogenic bacteria were used in this study (Pseudomonas aeruginosa, Staphylococcus aureus, and E. coli) in addition to one opportunistic yeast (Candida albicans). Nano-creatine particles can be used for wound dressing as well as cosmetic preparation.

Self-crosslinked keratin nanoparticles for pH and GSH dual responsive drug carriers

Nano-drug delivery system (NDDS) has attracted widespread attention for their controlled drug release. In this work, keratin nanoparticles (KNPs) were prepared by self-crosslinking. No toxic chemical crosslinkers were added in the whole procedure. The morphology and size of KNPs were tested by transmission electron microscopy (TEM) and dynamic light scattering (DLS), respectively. The KNPs exhibited GSH and pH dual responsiveness as well as charge conversion, which were beneficial to tumor therapy. In addition, the anticancer drug of doxorubicin (DOX) could be loaded on KNPs by hydrophobicity and hydrogen bonds. The drug-loaded keratin nanoparticles (KDNPs) accelerated drug release under mimicked tumor microenvironments. In addition, KDNPs could effectively inhibit tumor cell growth while performing low toxicity on normal cells. Moreover, KDNPs could be uptaken by tumor cells through endocytosis. Based on the results, keratin-based nanoparticles were suitable candidates for drug microcarriers.

Design, In Silico Modelling, and Functionality Theory of Novel Folate Receptor Targeted Rutin Encapsulated Folic Acid Conjugated Keratin Nanoparticles for Effective Cancer Treatment.

Site-specific and toxic-free drug delivery, is an interesting area of research. Nanoengineered drug delivery systems possess a remarkable potential for effective treatment of various types of cancers. In this study, novel Folic Acid (FA) conjugated keratin nanoparticles (NPs) were assembled with encapsulation and delivery of Rutin (Rt) into breast cancer cells through the overexpressed folate receptor. The biocompatible, Rt encapsulated FA conjugated keratin NPs (FA@Ker NPs) were successfully formulated by a modified precipitation technique. Their morphological shape and size, size distribution, stability, and physical nature were characterized and confirmed. The drug (Rt) encapsulation efficiency, loading capacity and release kinetics were also studied. The observed results of molecular docking and density functionality theory of active drug (Rt) showed a strong interaction and non-covalent binding of the folate receptor and facilitation of endocytosis in breast cancer cells. Further, in vitro cytotoxic effect of FA@Ker NPs was screened against MCF-7 cancer cells, at 55.2 µg/mL of NPs and found to display 50% of cell death at 24h. Moreover, the NPs enhanced the uptake of Rt in MCF-7 cells, and the apoptotic effect of condensed nuclei and distorted membrane bodies was observed. Also, NPs entered into the mitochondria of MCF-7 cells and significantly increased the level of ROS which led to cell death. The developed FA@Ker NPs might be a promising way to enhance anti-cancer activity without disturbing normal healthy cells.

Performance of keratin nanoparticle and its magnetic nanocomposite for Zn(II) removal from its aqueous solution

The comparative sorption studies were carried out to investigate the performance of keratin nanoparticles (KNPs) and magnetic KNPs (MKNPs) for Zn(II) uptake. MKNPs showed remarkably higher Zn(II) removal due to the lower keratin weight percent in its structure (8.4%). MKNPs revealed relatively uniform Zn(II) removal within pH range between 4.0 to 6.0 at the temperature of 25°C rather than KNPs. Both KNP and MKNP exhibited two-stage kinetic behavior and reached to their equilibrium adsorption capacity within 30 min. The adsorption of Zn(II) on KNPs and MKNPs followed pseudo second order kinetic model. It was found that the experimental data were best fitted to Sips or Redlich-Peterson isotherm when KNP was used as biosorbent. Unlike KNP, MKNP conformed better to Langmuir model. The maximum adsorption capacity of MKNP at two doses of 3.0 and 5.0 g/L was calculated to be 30 and 18 mg/g, respectively. As the dosage of MKNP raised from 3.0 to 5.0 g/L, the value of KL increased from 0.045 L/mg to 0.154 L/mg, confirming more biosorbent tendency to adsorb metal ions.

Keratin nanoparticles obtained from human hair for removal of crystal violet from aqueous solution: Optimized by Taguchi method

Developing the cheap but superior adsorbents is of importance for environmental applications. In this paper, the Taguchi experimental design was applied to establish the optimum condition for the removal of crystal violet (CV) dye using keratin nanoparticles obtained from human hair waste. The average diameter of keratin particles was found about 63.7 nm, using DLS. Effective factors on the removal of CV dye including pH, adsorbent dose, temperature and contact time were considered using an L16 orthogonal array. The optimum condition was found to be pH = 9, adsorbent dose = 0.004 g, temperature = 25 °C and contact time = 10 h in the studied range for different parameters. ANOVA results indicated that the pH has the highest contribution percentage (75.97%) on the adsorption process. Moreover, the equilibrium data were well described by Freundlich Isotherm, indicating a multilayer adsorption process with a maximum adsorption capacity of 555.56 mg/g through an endothermic and spontaneous adsorption process that could be used for up to 5 cycles of adsorption process. The kinetic adsorption data were evaluated by different kinetic models, where the data followed a pseudo-second-order model with three steps of diffusion indicated by the intra-particle diffusion model. The obtained results clearly show the high potential of human hair-obtained keratin nanoparticles for removal of cationic dyes from wastewater.

Design and in silico modeling of Indoloquinoxaline incorporated keratin nanoparticles for modulation of glucose metabolism in 3T3-L1 adipocytes.

The following study was done to assess the glucose utilizing efficiency of Indoloquinoxaline derivative incorporated keratin nanoparticles (NPs) in 3T3-L1 adipocytes. Indoloquinoxaline derivative had wide range of biological activities including antidiabetic activity. In this view, Indoloquinoxaline moiety containing N, N-dimethyl (3-fluoro-6H-indolo [3,2-b] quinoxalin-6-yl) methanamine compound was designed and synthesized, and further it is incorporated into keratin nanoparticles. The formulated NPs, drug entrapment efficiency, releasing capacity, stability, and physicochemical properties were characterized by various spectral analyzer and obtained results of characterizations were confirmed the properties of NPs. The analysis of mechanism underlying the glucose utilization of NPs was examined through molecular docking with identified target, and observed in silico study reports shown strong interaction of NPs in the binding pockets of AMPK and PTP1B. Based on the in silico screening, the formulated NPs was performed for in vitro cellular viability and glucose uptake studies on 3T3-L1 adipocytes. Interestingly, 40 μg of NPs displayed 78.2 ± 2.76% cellular viability, and no cell death was observed at lower concentrations. Further, the concentration dependent glucose utilization was observed at different concentrations of NPs in 3T3-L1 adipocytes. The results of NPs (40 μg) on glucose utilization have revealed eminent result 58.56 ± 4.54% compared to that of Metformin (10 μM) and Insulin (10 μM). The identified results clearly indicated that Indoloquinoxaline derivative incorporated keratin NPs significantly increased glucose utilization efficiency and protect the cells against the insulin resistance.

Keratin nanoparticles co-delivering Docetaxel and Chlorin e6 promote synergic interaction between chemo- and photo-dynamic therapies

The combination of chemotherapy and photodynamic therapy (PDT) is considered a valuable strategy for increasing therapeutic response in cancer treatment, and the re-formulation of pharmaceuticals in biocompatible nanoparticles (NPs) is particularly appealing for the possibility of co-loading drugs exerting cytotoxicity by different mechanisms, with the aim to produce synergic effects. We report the in-water synthesis of a novel keratin-based nanoformulation for the co-delivery of the antimitotic Docetaxel (DTX) and the photosensitizer Chlorin e6 (Ce6). The drug-induced aggregation method allowed the formation of monodisperse NPs (DTX/Ce6-KNPs) with an average diameter of 133 nm and loaded with a drug ratio of 1:1.8 of Ce6 vs DTX. The efficacy of DTX/Ce6-KNPs was investigated in vitro in monolayers and spheroids of DTX-sensitive HeLa (HeLa-P) and DTX-resistant HeLa (HeLa-R) cells. In monolayers, the cytotoxic effects of DTX/Ce6-KNPs toward HeLa-P cells were comparable to those induced by free DTX + Ce6, while in HeLa-R cells the drug co-loading in KNPs produced synergic interaction between chemotherapy and PDT. Moreover, as respect to monotherapies, DTX/Ce6-KNPs induced stronger cytotoxicity to both HeLa-P and HeLa-R multicellular spheroids and reduced their volumes up to 50%. Overall, the results suggest that KNPs are very promising systems for the co-delivery of chemotherapeutics and PSs, favoring synergic interactions between PDT and chemotherapy.