Chitosan-coated liposomes to stabilize and enhance transdermal delivery of indocyanine green for photodynamic therapy of melanoma

Chitosan- and hyaluronic acid-based nanoarchitectures in phototherapy: Combination cancer chemotherapy, immunotherapy and gene therapy

Cancer phototherapy has introduced a new potential modality for tumor suppression. However, the efficacy of phototherapy has been limited due to a lack of targeted delivery of photosensitizers. Therefore, the application of biocompatible and multifunctional nanoparticles in phototherapy is appreciated. Chitosan (CS) as a cationic polymer and hyaluronic acid (HA) as a CD44-targeting agent are two widely utilized polymers in nanoparticle synthesis and functionalization. The current review focuses on the application of HA and CS nanostructures in cancer phototherapy. These nanocarriers can be used in phototherapy to induce hyperthermia and singlet oxygen generation for tumor ablation. CS and HA can be used for the synthesis of nanostructures, or they can functionalize other kinds of nanostructures used for phototherapy, such as gold nanorods. The HA and CS nanostructures can combine chemotherapy or immunotherapy with phototherapy to augment tumor suppression. Moreover, the CS nanostructures can be functionalized with HA for specific cancer phototherapy. The CS and HA nanostructures promote the cellular uptake of genes and photosensitizers to facilitate gene therapy and phototherapy. Such nanostructures specifically stimulate phototherapy at the tumor site, with particle toxic impacts on normal cells. Moreover, CS and HA nanostructures demonstrate high biocompatibility for further clinical applications.

Indocyanine green-loaded N-doped carbon quantum dot nanoparticles for effective photodynamic therapy and cell imaging of melanoma cancer: In vitro, ex vivo and in vivo study

N-doped carbon quantum dot (CQD) nanoparticle was prepared as a novel nanocarrier with excellent solubility, stability, and high quantum yield to overcome Indocyanine Green (ICG) obstacle in photodynamic therapy (PDT) with simultaneous cell imaging property. Cell culture study and In vivo assessments on the C57BL/6 mice containing melanoma cancer cells was performed. Results showed that CQD size after ICG loading slightly enhanced from 24.55 nm to 42.67 nm. Detection of reactive oxygen species (ROS) test demonstrated that CQD improved ICG photo-stability and ROS generation capacity upon laser irradiation. Cell culture study illustrated that ICG@CQD could decrease the survival rate of melanoma cancer cells of B16F10 cell line from 48% for pure ICG drug to 28% for ICG@CQD. Captured images by confocal microscopy approved more cellular uptake of ICG@CQD and more qualified cell imaging ability of the nanocarrier. In vivo assessments on the C57BL/6 mice containing melanoma cancer cells displayed the obvious inhibitory effect of the tumor growth for ICG@CQD in comparison to free ICG. In vivo fluorescence images confirmed that ICG@CQD accumulates remarkably more than free ICG in the tumor region. In conclusion, ICG@CQD is proposed as an innovative nanocarrier with great potential for PDT and diagnosis.

Transdermal Delivery of Recombinant Human Growth Hormone by Liposomal Gel for Skin Photoaging Therapy

Human growth hormone (hGH) has emerged as a promising therapeutic agent to prevent and treat skin photoaging. However, the success of hGH therapy largely lies in the availability of an optimal delivery system that enables the efficient delivery of hGH to the dermal layer of the skin. Here, we report a delivery system of hyaluronic acid/liposome-gel-encapsulated hGH (HA/HL-Gel) that can transdermally deliver hGH into the skin for hGH-based photoaging therapy through the upregulation of collagen type I (collagen-I). Specifically, hGH-liposomes were prepared by ethanol injection and then modified with HA to achieve specific targeting. The best formulation of HA/hGH-liposomes (HA/HL) had a high encapsulation efficiency (about 20%), with a size of 180 ± 1.2 nm. The optimized HA/HL was further incorporated into the carbomer gel to form an HA/HL-Gel. The biological activity of HA/HL on human dermal fibroblasts (HDFs) was confirmed by the elevated expression level of collagen-I through the enhanced local formation of insulin-like growth factor-1 (IGF-1) in the photoaging model. Moreover, HA/HL-Gel reduced ultraviolet (UV)-induced erythema and wrinkle formation. Meanwhile, immunohistochemical staining further showed higher levels of collagen-I in the HA/HL-Gel group compared to other groups tested. Taken together, these results demonstrate that HA/HL-Gel treatment could significantly ameliorate skin photoaging and thus may be used as a clinical potential for antiaging therapy.

Techniques, applications and prospects of polysaccharide and protein based biopolymer coatings: A review

The growing relevance of sustainable materials has recently led to the exploration of naturally derived biopolymeric hydrogels as coating materials due to their biodegradability, biocompatibility, ease of fabrication and modification. Although many review articles exist on biopolymeric coatings, they mainly focus on a specific polysaccharide, protein biopolymer, or a particular application- biomedical engineering or food preservation. The current review first summarizes the commonly used polysaccharide and protein-based biopolymers like chitosan, alginate, carrageenan, pectin, cellulose, starch, pullulan, agarose and silk fibroin, gelatin, respectively, with a systematic description of the techniques widely used for physical coating on substrates. Then, broad applications of these biopolymeric coatings on various substrates in biomedical engineering- 3D scaffolds, biomedical implants, and nanoparticles are described in detail. It also entails the application of biopolymeric coatings for food preservation in the form of food packaging and edible coatings. A brief discussion on the newly discovered interest in exploring biopolymers for anticorrosive coating applications is also included. Finally, concluding remarks on the role of biopolymer microstructures in forming homogeneous coatings, prospective alternatives to the currently used biopolymers as coating material and the advent of computer-aided technologies to expedite experimental findings are presented.

The fusion of light and immunity: Advancements in photoimmunotherapy for melanoma

Metastatic melanoma is an aggressive skin cancer with high mortality and recurrence rates. Despite the clinical success of recent immunotherapy approaches, prevailing resistance rates necessitate the continued development of novel therapeutic options. Photoimmunotherapy (PIT) is emerging as a promising immunotherapy strategy that uses photodynamic therapy (PDT) to unleash systemic immune responses against tumor sites while maintaining the superior tumor-specificity and minimally invasive nature of traditional PDT. In this review, we discuss recent advances in PIT and strategies for the management of melanoma using PIT. PIT can strongly induce immunogenic cell death, inviting the concomitant application of immune checkpoint blockade or adoptive cell therapies. PIT can also be leveraged to selectively remove the suppressive immune populations associated with immunotherapy resistance. The modular nature of PIT therapy design combined with the potential for patient-specific antigen selection or drug co-delivery makes PIT an alluring option for future personalized melanoma care.

Preparation of pectin-coated and chitosan-coated phenylethanoside liposomes: Studies on characterization, stability, digestion and release behavior

In this paper, the effects of extrusion, ultrasound on physicochemical properties of liposomes were studied, and the liposomes were prepared by ethanol injection combined with extrusion-ultrasound. In addition, the quality of PhGs lips, pectin-coated PhGs lips (P-lips) and chitosan-coated PhGs lips (C-lips) was evaluated by the average particle size, encapsulation efficiency (EE) and other indicators, which indicated that the nanoparticles had been successfully prepared. Compared with extrusion or ultrasonic operation alone, the EEs of ethanol injection combined with extrusion-ultrasonic increased by 8 % and 18 % respectively. Subsequently, transmission electron microscopy, Fourier transform infrared spectroscopy and DSC thermal analysis showed that PhGs in PhGs lips may produce hydrogen bonding forces with phospholipids, and pectin and chitosan in P-lips and C-lips were not only coated on the surface of PhGs lips, but also might have some interaction between them. Cell experiments showed that PhGs lips, P-lips and C-lips can effectively improve the bioavailability of PhGs. In addition, the storage stability of P-lips and C-lips was not significantly improved compared to PhGs lips, but their digestive stability was significantly improved, and the final retention rate in simulated intestinal fluid was about 25 % higher than that of PhGs lips.

Cutaneous Pharmacokinetics of Topically Applied Novel Dermatological Formulations

Novel formulations are developed for dermatological applications to address a wide range of patient needs and therapeutic challenges. By pushing the limits of pharmaceutical technology, these formulations strive to provide safer, more effective, and patient-friendly solutions for dermatological concerns, ultimately improving the overall quality of dermatological care. The article explores the different types of novel dermatological formulations, including nanocarriers, transdermal patches, microsponges, and microneedles, and the techniques involved in the cutaneous pharmacokinetics of these innovative formulations. Furthermore, the significance of knowing cutaneous pharmacokinetics and the difficulties faced during pharmacokinetic assessment have been emphasized. The article examines all the methods employed for the pharmacokinetic evaluation of novel dermatological formulations. In addition to a concise overview of earlier techniques, discussions on novel methodologies, including tape stripping, in vitro permeation testing, cutaneous microdialysis, confocal Raman microscopy, and matrix-assisted laser desorption/ionization mass spectrometry have been conducted. Emerging technologies like the use of microfluidic devices for skin absorption studies and computational models for predicting drug pharmacokinetics have also been discussed. This article serves as a valuable resource for researchers, scientists, and pharmaceutical professionals determined to enhance the development and understanding of novel dermatological drug products and the complex dynamics of cutaneous pharmacokinetics.

Novel Chitosan-Coated Liposomes Coloaded with Exemestane and Genistein for an Effective Breast Cancer Therapy

For achieving high effectiveness in the management of breast cancer, coadministration of drugs has attracted a lot of interest as a mode of therapy when compared to a single chemotherapeutic agent that often results in reduced therapeutic end results. Owing to their proven effectiveness, good patient compliance, and lower costs, oral anticancer drugs have received much attention. In the present work, we formulated the chitosan-coated nanoliposomes loaded with two lipophilic agents, namely, exemestane (EXE) and genistein (GEN). The formulation was prepared using the ethanol injection method, which is considered a simple method for getting the nanoliposomes. The formulation was optimized using Box-Behnken design (BBD) and was extensively characterized for particle size, ζ-potential, Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) analysis. The sizes of conventional and coated liposomes were found to be 104.6 ± 3.8 and 120.3 ± 6.4 nm with a low polydispersity index of 0.399 and 0.381, respectively. The ζ-potential of the liposomes was observed to be -16.56 mV, which changed to a positive value of +22.4 mV, clearly indicating the complete coating of the nanoliposomes by the chitosan. The average encapsulation efficiency was found to be between 70 and 80% for all prepared formulations. The compatibility of the drug with excipients and complete dispersion of the drug inside the system were verified by FTIR, XRD, and DSC studies. Furthermore, the in vitro release studies concluded the sustained release pattern following the Korsmeyer-Peppas model as the best-fitting model with Fickian diffusion. Ex vivo studies showed better permeation of the chitosan-coated liposomes, which was further confirmed by confocal studies. The prepared chitosan-coated liposomes showed superior antioxidant activity (94.56%) and enhanced % cytotoxicity (IC50 7.253 ± 0.34 μM) compared to the uncoated liposomes. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay displayed better cytotoxicity of the chitosan-coated nanoliposomes compared to the plain drug, showing the better penetration and enhanced bioavailability of drugs inside the cells. The formulation was found to be safe for administration, which was confirmed using the toxicity studies performed on an animal model. The above data suggested that poorly soluble lipophilic drugs could be successfully delivered via chitosan-coated liposomes for their effective delivery in breast cancer.

A Novel Strategy for Topical Administration by Combining Chitosan Hydrogel Beads with Nanostructured Lipid Carriers: Preparation, Characterization, and Evaluation

The objective of the present study was to develop and evaluate NLC-chitosan hydrogel beads for topical administration. The feasibility of the preparation technology was verified by investigating various formulation factors and the impact of chitosan hydrogel beads on the NLC. The encapsulation efficiency of NLC-chitosan hydrogel beads was above 95% in optimized process conditions. The physical characterization of the NLC-chitosan hydrogel beads showed that the NLC was distributed within the network of the chitosan hydrogel beads. Furthermore, the incorporation of NLC into the chitosan hydrogel beads was related to the electrostatic interaction between the surface of the NLC and chitosan, which influenced the lipid ordering degree of the NLC and contributed to the stability. The stability studies showed that the retention rate of quercetin in the NLC-chitosan hydrogel beads was 88.63 ± 2.57% after 10 months of storage under natural daylight. An in vitro permeation study showed that NLC-chitosan hydrogel beads exhibited superior ability in enhancing skin permeation by hydrophobic active ingredients compared to the NLC and significantly increased skin accumulation. These studies demonstrated that the use of NLC-chitosan hydrogel beads might be a promising strategy for the delivery of hydrophobic active ingredients in topical administration.

Nanocarriers in topical photodynamic therapy

INTRODUCTION

Photodynamic therapy (PDT) has gained significant attention due to its superiority over conventional treatments. In the context of skin cancers and nonmalignant skin diseases, topical application of photosensitizer formulations onto affected skin, followed by illumination, offers distinct advantages. Topical PDT simplifies therapy by providing easy access to the skin, increasing drug concentration within the target area, and confining residual photosensitivity to the treated skin. However, the effectiveness of topical PDT is often hindered by challenges such as limited skin penetration or photosensitizer instability. Additionally, the hypoxic tumor environment poses further limitations. Nanocarriers present a promising solution to address these challenges.

AREAS COVERED

The objective of this review is to comprehensively explore and highlight the role of various nanocarriers in advancing topical PDT for the treatment of skin diseases. The primary focus is to address the challenges associated with conventional topical PDT approaches and demonstrate how nanotechnology-based strategies can overcome these challenges, thereby improving the overall efficiency and efficacy of PDT.

EXPERT OPINION

Nanotechnology has revolutionized the field of PDT, offering innovative tools to combat the unfavorable features of photosensitizers and hurdles in PDT. Nanocarriers enhance skin penetration and stability of photosensitizers, provide controlled drug release, reduce needed dose, increase production of reactive oxygen species, while reducing side effects, thereby improving PDT effectiveness.

Pre-mixing of omega-3 fatty acid-containing liposomes enhances the drug release rate and therapeutic efficacy of anticancer drugs loaded in liposomes

The therapeutic efficacy of anticancer drugs loaded in liposomes composed of rigid phosphatidylcholine (PC) is hindered by the limited release of these drugs at the tumor site, which in turn hampers delivery of the drug to its intracellular target. In an attempt to improve the therapeutic efficacy of liposomal anticancer drugs, we here explored the use of empty liposomes as "trigger" vehicles to induce drug release from drug-loaded liposomes through liposome-liposome interactions. Empty liposomes containing PC in which omega-3 fatty acids comprised both fatty acid strands (Omega-L) showed a triggering effect on drug release from doxorubicin (DOX)-loaded liposomes (Caelyx). The effectiveness of this triggered-release effect was dependent on the Omega-L composition as well as the mixing ratio of Omega-L to Caelyx. Cryo-TEM and differential calorimetry studies revealed that the Omega-L effect was associated with liposome-liposome interactions that led to loosened membrane packing and increased fluidity of Caelyx. In cultured cells, the intracellular/intranuclear DOX uptake and anticancer efficacy of Caelyx was greatly improved by Omega-L pre-mixing. Intravenous injection of rats with Caelyx, premixed with Omega-L, decreased the area under the plasma concentration-time curve from time zero to time infinity and increased clearance without significantly changing the mean residence time or terminal half-life of DOX compared with Caelyx alone. Ex vivo bioimaging showed that DOX fluorescence in tumors, but not in other organs, was significantly increased by Omega-L premixing. In the mouse xenograft model, premixing of Omega-L with Caelyx suppressed tumor growth 2.5-fold compared with Caelyx. Collectively, the data provide preliminary evidence that the Omega-L-triggered drug release that occurs before and after dosing, particularly at tumor site, improved the therapeutic efficacy of Caelyx. The simple approach described here could enhance the therapeutic value of Caelyx and other anticancer drug-loaded liposomes.

Flavonoid-Labeled Biopolymer in the Structure of Lipid Membranes to Improve the Applicability of Antioxidant Nanovesicles

Nanovesicles produced with lipids and polymers are promising devices for drug and bioactive delivery and are of great interest in pharmaceutical applications. These nanovesicles can be engineered for improvement in bioavailability, patient compliance or to provide modified release or enhanced delivery. However, their applicability strongly depends on the safety and low immunogenicity of the components. Despite this, the use of unsaturated lipids in nanovesicles, which degrade following oxidation processes during storage and especially during the proper routes of administration in the human body, may yield toxic degradation products. In this study, we used a biopolymer (chitosan) labeled with flavonoid (catechin) as a component over a lipid bilayer for micro- and nanovesicles and characterized the structure of these vesicles in oxidation media. The purpose of this was to evaluate the in situ effect of the antioxidant in three different vesicular systems of medium, low and high membrane curvature. Liposomes and giant vesicles were produced with the phospholipids DOPC and POPC, and crystalline cubic phase with monoolein/DOPC. Concentrations of chitosan-catechin (CHCa) were included in all the vesicles and they were challenged in oxidant media. The cytotoxicity analysis using the MTT assay (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) revealed that concentrations of CHCa below 6.67 µM are non-toxic to HeLa cells. The size and zeta potential of the liposomes evidenced the degradation of their structures, which was minimized by CHCa. Similarly, the membrane of the giant vesicle, which rapidly deteriorated in oxidative solution, was protected in the presence of CHCa. The production of a lipid/CHCa composite cubic phase revealed a specific cubic topology in small-angle X-ray scattering, which was preserved in strong oxidative media. This study demonstrates the specific physicochemical characteristics introduced in the vesicular systems related to the antioxidant CHCa biopolymer, representing a platform for the improvement of composite nanovesicle applicability.

Lidocaine-Liposomes-A Promising Frontier for Transdermal Pain Management

(1) Background: We aim to develop novel gel formulations for transdermal drug delivery systems in acute and inflammatory pain therapy. (2) Methods: We induced inflammation by the injection of λ-carrageenan on the hind paw of 80 Wistar male rats. The animals were randomized into eight groups of 10 rats each: C (placebo gel), E (EMLATM), L (lidocaine 2%), L-CD (lidocaine + cyclodextrin 2.5%), L-LP (lidocaine + liposomes 1.7%), L-CS (lidocaine + chitosan 4%), L-CSh (lidocaine + chitosan hydrochloride), and L-CS-LP (lidocaine + chitosan + liposomes). The behavior response was determined with a hot plate, cold plate, and algesimeter, each being performed at 30, 60, 120, 180, and 240 min after pain induction. At the end of the experiment, tissue samples were collected for histological assessment. (3) Results: L-LP had the greatest anesthetic effects, which was proven on the cold plate test compared to placebo and EMLATM (all p ≤ 0.001). L-CS-LP had a significant effect on cold plate evaluation compared to placebo (p ≤ 0.001) and on hot plate evaluation compared to EMLATM (p = 0.018). (4) Conclusions: L-LP is a new substance with a substantial analgesic effect demonstrated by the cold plate in the first 120 min. Further studies with more animals are needed to determine the maximum doses that can be applied for a better analgesia with minimum side effects.

Enhancing stability of liposomes using high molecular weight chitosan to promote antioxidative stress effects and lipid-lowering activity of encapsulated lutein in vivo and in vitro

Lutein is an antioxidant with multiple beneficial functions. However, its therapeutic potential is hampered by its low water solubility and bioavailability. The goal of this study is to compare the stability of lutein-loaded liposomes (Lu-lip) and low (LC)/high molecular weight (HC) chitosan-coated Lu-lip, along with their antioxidant capacity using H2O2-induced HepG2 cells and their lipid-lowering activity using high-fat diet mice. Both LC and HC reduced the lutein degradation rate by 17.5 % and 26.72 % in a challenging environment at pH 6 and T = 4 °C. Compared to LC, the HC coating improved the size- and zeta-potential-stability of Lu-lip at 5 < pH < 7, with the best performance at pH 6. The HC coating prolonged the lutein release profile, increased the cellular uptake of Lu-lip, and reduced the reactive oxygen species (ROS) levels and the H2O2-induced necrotic cell ratios by increasing the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Animal experiments have shown that oral administration of LC and HC coated Lu-lip can significantly reduce body weight levels, total triglycerides (TG), total cholesterol (TC), and non-high-density lipoprotein (n-HDL-C) in high-fat diet mice while significantly increasing the levels of CAT, SOD and GSH-Px in the liver of mice. LC and HC coated Lu-lip can reduce fat accumulation in the liver and epididymal adipose tissue.

A Snapshot of Photoresponsive Liposomes in Cancer Chemotherapy and Immunotherapy: Opportunities and Challenges

To provide precise medical regimens, photonics technologies have been involved in the field of nanomedicine. Phototriggered liposomes have been cast as promising nanosystems that achieve controlled release of payloads in several pathological conditions such as cancer, autoimmune, and infectious diseases. In contrast to the conventional liposomes, this photoresponsive element greatly improves therapeutic efficacy and reduces the adverse effects of gene/drug therapy during treatment. Recently, cancer immunotherpay has been one of the hot topics in the field of oncology due to the great success and therapeutic benefits that were well-recognized by the patients. However, several side effects have been encountered due to the unmonitored augmentation of the immune system. This Review highlights the most recent advancements in the development of photoresponsive liposome nanosystems in the field of oncology, with a specific emphasis on challenges and opportunities in the field of cancer immunotherapy.

Photosensitizers-Loaded Nanocarriers for Enhancement of Photodynamic Therapy in Melanoma Treatment

Malignant melanoma poses a significant global health burden. It is the most aggressive and lethal form of skin cancer, attributed to various risk factors such as UV radiation exposure, genetic modifications, chemical carcinogens, immunosuppression, and fair complexion. Photodynamic therapy is a promising minimally invasive treatment that uses light to activate a photosensitizer, resulting in the formation of reactive oxygen species, which ultimately promote cell death. When selecting photosensitizers for melanoma photodynamic therapy, the presence of melanin should be considered. Melanin absorbs visible radiation similar to most photosensitizers and has antioxidant properties, which undermines the reactive species generated in photodynamic therapy processes. These characteristics have led to further research for new photosensitizing platforms to ensure better treatment results. The development of photosensitizers has advanced with the use of nanotechnology, which plays a crucial role in enhancing solubility, optical absorption, and tumour targeting. This paper reviews the current approaches (that use the synergistic effect of different photosensitizers, nanocarriers, chemotherapeutic agents) in the photodynamic therapy of melanoma.

Polysaccharide-modified liposomes and their application in cancer research

Nanodrug delivery systems have been widely used in cancer treatment. Among these, liposomal drug carriers have gained considerable attention due to their biocompatibility, biodegradability, and low toxicity. However, conventional liposomes have several shortcomings, such as poor stability, rapid clearance, aggregation, fusion, degradation, hydrolysis, and oxidation of phospholipids. Polysaccharides are natural polymers of biological origin that exhibit structural stability, excellent biocompatibility and biodegradability, flexibility, non-immunogenicity, low toxicity, and targetability. Therefore, they represent a promising class of polymers for the modification of the surface properties of liposomes to overcome their shortcomings. In addition, polysaccharides can be readily combined with other materials to develop new composite materials. Hence, they represent the optimal choice for liposomal modification to improve pharmacokinetics and clinical utility. Polysaccharide-coated liposomes exhibit better stability, drug release kinetics, and cellular uptake than conventional liposomes. The oncologic application of polysaccharide-coated liposomes has become a research hotspot. We summarize the preparation, physicochemical properties, and antineoplastic effects of polysaccharide-coated liposomes to facilitate antitumor drug development.

Calcium-peroxide-mediated cascades of oxygen production and glutathione consumption induced efficient photodynamic and photothermal synergistic therapy

Photodynamic therapy (PDT) and photothermal therapy (PTT) are potent approaches to cancer treatment. However, the tumor microenvironment (TME) characterized by severe hypoxia and abundant glutathione (GSH) significantly reduces the effectiveness of PDT. In this study, we developed an oxidative stress amplifier CaO₂/ICG@ZIF-8, which was capable of self-sufficient O₂ delivery and GSH depletion to enhance PDT and PTT synergistic therapy. We utilized ZIF-8 as nanocarriers that when loaded with CaO₂ and indocyanine green (ICG) form CaO₂/ICG@ZIF-8 nanoparticles, which exhibit a uniform particle size distribution and a hydrated particle size of about 215 nm. CaO₂ reacts with water under acidic conditions to produce O₂ so CaO₂/ICG@ZIF-8 has an excellent O₂ supply capacity, which is essential for PDT. Moreover, CaO₂/ICG@ZIF-8 also reacts with GSH to form glutathione disulfides (GSSH), enhancing the therapeutic outcome of PDT by preventing the consumption of local ractive oxygen species. Beyond that, CaO₂/ICG@ZIF-8 can produce strong hyperthermia with a photothermal conversion efficiency of about 44%, which is exceedingly appropriate for PTT. Owing to its augmentation, PTT/PDT mediated by CaO₂/ICG@ZIF-8 demonstrates intense tumor inhibitory effects in both in vitro and in vivo studies. Notably, the Zn and Ca generated by CaO₂/ICG@ZIF-8 degradation are essential elements for the body, so CaO₂/ICG@ZIF-8 shows favorable safety. Altogether, the research provides a promising PDT/PTT synergistic therapeutic strategy for cancer and may show more medical applications in the future.

Quatsomes Loaded with Squaraine Dye as an Effective Photosensitizer for Photodynamic Therapy

Photodynamic therapy is a non-invasive therapeutic strategy that combines external light with a photosensitizer (PS) to destroy abnormal cells. Despite the great progress in the development of new photosensitizers with improved efficacy, the PS’s photosensitivity, high hydrophobicity, and tumor target avidity still represent the main challenges. Herein, newly synthesized brominated squaraine, exhibiting intense absorption in the red/near-infrared region, has been successfully incorporated into Quatsome (QS) nanovesicles at different loadings. The formulations under study have been characterized and interrogated in vitro for cytotoxicity, cellular uptake, and PDT efficiency in a breast cancer cell line. The nanoencapsulation of brominated squaraine into QS overcomes the non-water solubility limitation of the brominated squaraine without compromising its ability to generate ROS rapidly. In addition, PDT effectiveness is maximized due to the highly localized PS loadings in the QS. This strategy allows using a therapeutic squaraine concentration that is 100 times lower than the concentration of free squaraine usually employed in PDT. Taken together, our results reveal the benefits of the incorporation of brominated squaraine into QS to optimize their photoactive properties and support their applicability as photosensitizer agents for PDT.

Formulation and Characterization of Ethyl Cellulose-Based Patches Containing Curcumin-Chitosan Nanoparticles for the Possible Management of Inflammation via Skin Delivery

Curcumin, a natural phenolic compound, exhibits poor absorption and extensive first pass metabolism after oral administration. In the present study, curcumin-chitosan nanoparticles (cur-cs-np) were prepared and incorporated into ethyl cellulose patches for the management of inflammation via skin delivery. Ionic gelation method was used for the preparation of nanoparticles. The prepared nanoparticles were evaluated for size, zetapotential, surface morphology, drug content, and % encapsulation efficiency. The nanoparticles were then incorporated into ethyl cellulose-based patches using solvent evaporation technique. ATR-FTIR was used to study/assess incompatibility between drug and excipients. The prepared patches were evaluated physiochemically. The in vitro release, ex vivo permeation, and skin drug retention studies were carried out using Franz diffusion cells and rat skin as permeable membrane. The prepared nanoparticles were spherical, with particle size in the range of 203–229 nm, zetapotential 25–36 mV, and PDI 0.27–0.29 Mw/Mn. The drug content and %EE were 53% and 59%. Nanoparticles incorporated patches are smooth, flexible, and homogenous. The in vitro release and ex vivo permeation of curcumin from nanoparticles were higher than the patches, whereas the skin retention of curcumin was significantly higher in case of patches. The developed patches deliver cur-cs-np into the skin, where nanoparticles interact with skin negative charges and hence result in higher and prolonged retention in the skin. The higher concentration of drug in the skin helps in better management of inflammation. This was shown by anti-inflammatory activity. The inflammation (volume of paw) was significantly reduced when using patches as compared to nanoparticles. It was concluded that the incorporation of cur-cs-np into ethyl cellulose-based patches results in controlled release and hence enhanced anti-inflammatory activity.

Enhanced Tumor Accumulation of Low-Molecular-Weight Hyaluronic Acid/Chitosan Nanocomplexes for Photothermal Therapy

Targeted phototheranostic nanosystems involving both cancer-specific near-infrared (NIR) fluorescence imaging and NIR light-induced phototherapy have shown great potential to improve cancer detection and treatment. In this study, a bifunctional nanocomplex based on low-molecular-weight hyaluronic acid (LMW-HA) and chitosan oligosaccharide lactate (COL) conjugating a zwitterionic NIR dye (ZW800-1) was rationally designed and prepared, and it was simultaneously used to enhance tumor accumulation and photothermal therapy (PTT). When HA-COL-ZW nanocomplexes were intravenously injected into mice bearing NCI-H460 tumors, HA-COL-ZW revealed increased tumor accumulation with prolonged tumor retention. Moreover, the ZW800-1 incorporated in HA-COL-ZW nanocomplexes showed excellent capability to convert NIR light into heat energy at the tumor site, acting as a PTT agent. Therefore, the targeted phototherapeutic HA-COL-ZW nanocomplex is a biocompatible and effective photothermal nanoagent, which could be a good candidate for future clinical use.

Melanoma Cell Reprogramming and Awakening of Antitumor Immunity as a Fingerprint of Hyper-Harmonized Hydroxylated Fullerene Water Complex (3HFWC) and Hyperpolarized Light Application In Vivo

In our recent study, we showed that in vitro treatment of melanoma cells with hyperpolarized light (HPL) as well as with the second derivative of fullerene, hyper-harmonized hydroxylated fullerene water complex (3HFWC) reduced viability of cells by decreasing their proliferative capacity and inducing senescence and reprogramming towards a normal, melanocytic phenotype. Therefore, we wanted to determine whether these effects persisted in vivo in the syngeneic mouse melanoma model with a combined treatment of HPL irradiation and 3HFWC per os. Our results demonstrated the potent antitumor effects of 3HFWC nanosubstance assisted by HPL irradiation. These effects were primarily driven by the stimulation of melanoma cell growth arrest, the establishment of a senescent phenotype, and melanocytic differentiation on the one hand, and the awakening of the antitumor immune response on the other. In addition, the combined treatment reduced the protumorigenic activity of immune cells by depleting T regulatory cells, myeloid-derived suppressors, and M2 macrophages. The support of the 3HFWC substance by HPL irradiation may be the axis of the new approach design based on tumor cell reprogramming synchronized with the mobilization of the host's protective immune response.

Spontaneous Transfer of Indocyanine Green from Liposomes to Albumin Is Inhibited by the Antioxidant α-Tocopherol

Indocyanine Green (ICG) is a clinically approved organic dye with near-infrared absorption and fluorescence. Over the years, many efforts to improve the photophysical and pharmacokinetic properties of ICG have investigated numerous nanoparticle formulations, especially liposomes with membrane-embedded ICG. A series of systematic absorption and fluorescence experiments, including FRET experiments using ICG as a fluorescence energy acceptor, found that ICG transfers spontaneously from liposomes to albumin protein residing in the external solution with a half-life of ∼10 min at 37 °C. Moreover, transfer of ICG from liposome membranes to external albumin reduces light-activated leakage from thermosensitive liposomes with membrane-embedded ICG. A survey of lipophilic liposome additives discovered that the presence of clinically approved antioxidant, α-tocopherol, greatly increases ICG retention in the liposomes (presumably by forming favorable aromatic stacking interactions), inhibits ICG photobleaching and prevents albumin-induced reduction of light-triggered liposome leakage. This new insight will help researchers with the specific task of optimizing ICG-containing liposomes for fluorescence imaging or phototherapeutics. More broadly, the results suggest a broader design concept concerning light triggered liposome leakage, that is, proximity of the light absorbing dye to the bilayer membrane is a critical design feature that impacts the extent of liposome leakage.

Accelerating skin regeneration and wound healing by controlled ROS from photodynamic treatment

Cellular metabolisms produce reactive oxygen species (ROS) which are essential for cellular signaling pathways and physiological functions. Nevertheless, ROS act as “double-edged swords” that have an unstable redox balance between ROS production and removal. A little raise of ROS results in cell proliferation enhancement, survival, and soft immune responses, while a high level of ROS could lead to cellular damage consequently protein, nucleic acid, and lipid damages and finally cell death. ROS play an important role in various pathological circumstances. On the contrary, ROS can show selective toxicity which is used against cancer cells and pathogens. Photodynamic therapy (PDT) is based on three important components including a photosensitizer (PS), oxygen, and light. Upon excitation of the PS at a specific wavelength, the PDT process begins which leads to ROS generation. ROS produced during PDT could induce two different pathways. If PDT produces control and low ROS, it can lead to cell proliferation and differentiation. However, excess production of ROS by PDT causes cellular photo damage which is the main mechanism used in cancer treatment. This review summarizes the functions of ROS in living systems and describes role of PDT in production of controllable ROS and finally a special focus on current ROS-generating therapeutic protocols for regeneration and wound healing.

Middle purity soy lecithin is appropriate for food grade nanoliposome: Preparation, characterization, antioxidant and anti-inflammatory ability

The purity of soy lecithin exerts significant impact on nanoliposome (NL) properties for food applications. In this study, three soy lecithin of different purity were used to prepare NL. LC-MS analysis confirmed soy lecithin of relatively low purify (50% and 70%) contains multiple natural phospholipids. NL produced by soy lecithin of middle purity (70%) is smaller and more stable than other counterparts. Ultimately, soy lecithin of 70% purity was selected to develop NL encapsulated crocetin (CR) as model payload and further coated by chitosan (CS). The structure characteristic, physicochemical properties, antioxidant activity and anti-inflammatory activity of crocetin nanoliposome (CR-NL) and chitosan coated crocetin nanoliposome (CS-CR-NL) were evaluated. NL encapsulation and CS coating significantly improve antioxidant and anti-inflammatory ability of CR, and prolong storage period of CR (p < 0.05). For food applications, soy lecithin of middle purity (70%) is cheaper and more appropriate than soy lecithin of high purity.

The Potential of Antibody Technology and Silver Nanoparticles for Enhancing Photodynamic Therapy for Melanoma

Melanoma is highly aggressive and is known to be efficient at resisting drug-induced apoptotic signals. Resection is currently the gold standard for melanoma management, but it only offers local control of the early stage of the disease. Metastatic melanoma is prone to recurrence, and has a poor prognosis and treatment response. Thus, the need for advanced theranostic alternatives is evident. Photodynamic therapy has been increasingly studied for melanoma treatment; however, it relies on passive drug accumulation, leading to off-target effects. Nanoparticles enhance drug biodistribution, uptake and intra-tumoural concentration and can be functionalised with monoclonal antibodies that offer selective biorecognition. Antibody–drug conjugates reduce passive drug accumulation and off-target effects. Nonetheless, one limitation of monoclonal antibodies and antibody–drug conjugates is their lack of versatility, given cancer’s heterogeneity. Monoclonal antibodies suffer several additional limitations that make recombinant antibody fragments more desirable. SNAP-tag is a modified version of the human DNA-repair enzyme, O6-alkylguanine-DNA alkyltransferase. It reacts in an autocatalytic and covalent manner with benzylguanine-modified substrates, providing a simple protein labelling system. SNAP-tag can be genetically fused with antibody fragments, creating fusion proteins that can be easily labelled with benzylguanine-modified payloads for site-directed delivery. This review aims to highlight the benefits and limitations of the abovementioned approaches and to outline how their combination could enhance photodynamic therapy for melanoma.

How to Treat Melanoma? The Current Status of Innovative Nanotechnological Strategies and the Role of Minimally Invasive Approaches like PTT and PDT

Melanoma is the most aggressive type of skin cancer, the incidence and mortality of which are increasing worldwide. Its extensive degree of heterogeneity has limited its response to existing therapies. For many years the therapeutic strategies were limited to surgery, radiotherapy, and chemotherapy. Fortunately, advances in knowledge have allowed the development of new therapeutic strategies. Despite the undoubted progress, alternative therapies are still under research. In this context, nanotechnology is also positioned as a strong and promising tool to develop nanosystems that act as drug carriers and/or light absorbents to potentially improve photothermal and photodynamic therapies outcomes. This review describes the latest advances in nanotechnology field in the treatment of melanoma from 2011 to 2022. The challenges in the translation of nanotechnology-based therapies to clinical applications are also discussed. To sum up, great progress has been made in the field of nanotechnology-based therapies, and our understanding in this field has greatly improved. Although few therapies based on nanoparticulate systems have advanced to clinical trials, it is expected that a large number will come into clinical use in the near future. With its high sensitivity, specificity, and multiplexed measurement capacity, it provides great opportunities to improve melanoma treatment, which will ultimately lead to enhanced patient survival rates.

Association of Indocyanine Green with Chitosan Oleate Coated PLGA Nanoparticles for Photodynamic Therapy

Indocyanine green (ICG) is a safe dye widely used in the biomedical field. Its photodynamic effect (PDT), originating from laser irradiation at 803 nm, opens interesting perspectives in theranostic applications. To overcome its low water stability, ICG can be shielded with nanoparticles (NPs). In this work, previously developed NPs based on poly lactic-co-glycolic acid (PLGA) coated with chitosan oleate (CS-OA) and loaded with resveratrol as a hydrophobic model drug have been proposed as an ICG carrier. These systems have been selected for their observed immunostimulatory properties. The possible loading of the dye by adsorption onto NP surface by electrostatic interaction was studied here in comparison with the encapsulation into the PLGA core. The ICG-chitosan (CS) interaction has been characterized by spectrophotometry, spectroscopy and in-cell in vitro assays. Fluorescence quenching was observed due to the ionic interaction between ICG and CS and was studied considering the dye:polymer stoichiometry and the effect of the NP dilution in cell culture medium (DMEM). The NP systems have been compared in vitro, assessing their behaviour in Caco-2 cell lines. A reduction in cell viability was observed after irradiation of ICG associated with NPs, evident also for the samples loaded by adsorption. These findings open the opportunity to exploit the association of PDT’s effect on ICG with the properties of CS-OA coated NPs, whose immunostimulatory effect can be associated with PDT mechanism in cancer therapy.

Physicochemical Characterization of Chitosan-Decorated Finasteride Solid Lipid Nanoparticles for Skin Drug Delivery

Finasteride is considered the drug of choice for androgenic alopecia and benign prostate hyperplasia. The aim of the study was to formulate nanodrug carriers of finasteride with enhanced retentive properties in the skin. The finasteride was formulated as solid lipid nanoparticles that were decorated with different concentrations of chitosan for improved retentive properties. Solid lipid nanoparticles (SLNs) were synthesized by “high-speed homogenization technique” using stearic acid as a solid lipid while PEG-6000 and Tween-80 were used as surfactants. The SLNs were evaluated for particle size, polydispersity index (PDI), zeta potential, drug entrapment efficiency, and drug release behavior. The mean particle size of SLNs was in the range of 10.10 nm to 144.2 nm. The PDI ranged from 0.244 to 0.412 while zeta potential was in the range of 8.9 mV to 62.6 mV. The drug entrapment efficiency in chitosan undecorated formulations was 48.3% while an increase in drug entrapment was observed in chitosan-decorated formulations (51.1% to 62%). The in vitro drug release studies of SLNs showed an extended drug release for 24 hours after 4 hours of initial burst release. The extended drug release was observed in chitosan-coated SLNs in comparison with uncoated nanoparticles. The permeation and retention study revealed higher retention of drug in the skin and low permeation with chitosan-decorated SLNs that ranged from 39.4 μg/cm² to 13.2 μg/cm². TEM images depicted spherical shape of SLNs. The stability study confirmed stable formulations in temperature range of 5°C and 40°C for three months. It is concluded from this study that the SLNs of finasteride were successfully formulated and chitosan decoration enhanced the drug retention in the skin layers. Therefore, these formulations could be used in androgenic alopecia and benign prostate hyperplasia to avoid the side effects, drug degradation, and prolonged use of drug with conventional oral therapy.

Chitosan-coated nanostructured lipid carriers for transdermal delivery of tetrahydrocurcumin for breast cancer therapy

Chitosan (Ch)-coated nanostructured lipid carriers (NLCs) have great potential for transdermal delivery with high localization of chemotherapeutics in breast cancer. This study used tetrahydrocurcumin (THC), a primary metabolite of curcumin with enhanced antioxidant and anticancer properties, as a model compound to prepare NLCs. Response surface methodology was employed to optimize THC-loaded Ch-coated NLCs (THC-Ch-NLCs) fabricated by high-shear homogenization. The optimized THC-Ch-NLCs had particle size of 244 ± 18 nm, zeta potential of -17.5 ± 0.5 mV, entrapment efficiency of 76.6 ± 0.2% and drug loading of 0.28 ± 0.01%. In vitro release study of THC-Ch-NLCs showed sustained release following the Korsmeyer-Peppas model with Fickian and non-Fickian diffusion at pH 7.4 and 5.5, respectively. THC-Ch-NLCs demonstrated significantly enhanced in vitro skin permeation, cell uptake, and remarkable cytotoxicity toward MD-MBA-231 breast cancer cells compared to the unencapsulated THC, suggesting Ch-NLCs as potential transdermal nanocarriers of THC for triple-negative breast cancer treatment.

Stability characterization for pharmaceutical liposome product development with focus on regulatory considerations: An update

Liposomes have several advantages, such as the ability to be employed as a carrier/vehicle for a variety of drug molecules and at the same time they are safe and biodegradable. In the recent times, compared to other delivery systems, liposomes have been one of the most well-established and commercializing drug products of new drug delivery methods for majority of therapeutic applications. On the other hand, it has several limitations, particularly in terms of stability, which impedes product development and performance. In this review, we reviewed all the potential instabilities (physical, chemical, and biological) that a formulation development scientist confronts throughout the development of liposomal formulations as along with the ways to overcome these challenges. We have also discussed the effect of microbiological contamination on liposomal formulations with a focus on the use of sterilization methods used to improve the stability. Finally, we have reviewed quality control techniques and regulatory considerations recommended by the agencies (USFDA and MHLW) for liposome drug product development.

Deoxycholic acid-chitosan coated liposomes combined with in situ colonic gel enhances renal fibrosis therapy of emodin

BACKGROUND

Renal fibrosis is the final common pathological feature of various chronic kidney diseases (CKD). Despite recent advances, development of new treatments strategy is needed. Emodin (EMO), an important ingredient of Chinese medicine, rhubarb (Polygonaceae Rheum palmatum l.), has been reported to inhibit the development of renal fibrosis effectively. However, the poor oral bioavailability of EMO and the insufficient monotherapy therapy compromise its efficacy.

PURPOSE

In order to enhance renal fibrosis therapy of emodin, an innovative combination therapy based on deoxycholic acid-chitosan coated liposomes (DCS-Lips) and in situ colonic gel (IGE) was developed.

METHODS

For one, the DCS-Lips were prepared via electrostatic interaction by mixing anionic conventional Lips with cationic DCS, deoxycholic acid conjugated on the backbone of chitosan. The cellular uptake of FITC-labeled DCS-Lips in Caco-2 cell monolayer was evaluated by CLSM and flow cytometry, respectively. Permeability study was carried out using Caco-2 cell monolayer. For another, EMO-loaded in situ colonic gel (EMO-IGE) was prepared by mixing EMO nanosuspensions and plain in situ gel, which was obtained by the cold method. The EMO-IGE was assessed for morphology, gelation temperature, viscosity and in vitro drug release. Finally, the therapeutic efficacy of the combination strategy, oral DCS-Lips formulations and in situ colonic gel, was evaluated in unilateral ureteral obstruction (UUO) rat model. Additionally, 16S rDNA sequencing was performed on rats faces to investigate whether the combination strategy improves the microbial dysbiosis in UUO rats.

RESULTS

The prepared DCS-Lips produced small, uniformly sized nanoparticles, and significantly enhanced the cellular uptake and in vitro permeability of EMO compared to non-coated liposomes. Moreover, the EMO-IGE was characterized by short gelation time, optimal gelling temperature, and excellent viscosity. In UUO model, the combination of DCS-Lips (gavage) and IGE (enema) attenuated renal fibrosis effectively. The results of 16S rDNA sequencing illustrated that IGE could restore the gut microbial dysbiosis of UUO rats.

CONCLUSION

Overall, the combination of DCS-Lips and EMO-IGE alleviated renal fibrosis effectively, resulting from the improved oral bioavailability of EMO by DCS-Lips and the restoration of gut microbiota by EMO-IGE, thus, presenting an innovative and promising potential for renal fibrosis treatment.

Cationic inulin as a new surface decoration hydrocolloid for improving the stability of liposomal nanocarriers

The aim of the present study was to investigate the cationization of inulin with Williamson's etherification method, and compare cationic inulin with unmodified inulin coatings for stabilizing nanoliposomes (NLPs). The synthetized cationic inulin was characterized by Fourier transforms infrared (FT-IR) spectroscopy, carbon hydrogen nitrogen (CHN) elemental analysis, and energy-dispersive X-ray spectroscopy. Three concentrations of inulin and cationic inulin (1, 2, and 4 mg/mL) were used for the coating of NLPs. The concentration of 4 mg/mL was found to be optimal for inulin and cationic inulin as surface coating, on the basis of particle size, zeta potential, and microstructural morphology. The lowest values of particle size (93.41 nm), polydispersity index (0.25), and negative zeta potential (-24.41 mV) were related to the coated NLPs with cationic inulin at a concentration of 4 mg/mL. The transmission electron microscopy image of the coated NLPs with cationic inulin exhibited a spherical and core-shell structure. The coated NLPs with cationic inulin showed the highest thermal stability, physical stability, and oxidative stability. In conclusion, cationic inulin coating conferred a stronger protection than the unmodified inulin coating of NLPs. The technique developed here can be applied for surface decoration of NLPs to improve their stability.

Combined Action of Hyper-Harmonized Hydroxylated Fullerene Water Complex and Hyperpolarized Light Leads to Melanoma Cell Reprogramming In Vitro

(1) Background: Their unique structure and electron deficiency have brought fullerenes into the focus of research in many fields, including medicine. The hyper-harmonized hydroxylated fullerene water complex (3HFWC) formulation has solved the limitations of the poor solubility and bioavailability of fullerenes. To achieve better antitumor activity, 3HFWC was combined with short-term irradiation of cells with hyperpolarized light (HPL) generated by the application of a nanophotonic fullerene filter in a Bioptron^® device. The benefits of HPL were confirmed in the microcirculation, wound healing and immunological function. (2) Methods: B16, B16-F10 and A375 melanoma cells were exposed to a wide spectrum of 3HFWC doses and to a single short-term HPL irradiation. (3) Results: Apart from the differences in the redox status and level of invasiveness, the effects of the treatments were quite similar. Decreased viability, morphological alteration, signs of melanocytic differentiation and cellular senescence were observed upon the successful internalization of the nanoquantum substance. (4) Conclusions: Overall, 3HFWC/HPL promoted melanoma cell reprogramming toward a normal phenotype.

Mechanism and Application of Chitosan and Its Derivatives in Promoting Permeation in Transdermal Drug Delivery Systems: A Review

The mechanisms and applications of chitosan and its derivatives in transdermal drug delivery to promote drug permeation were reviewed in this paper. Specifically, we summarized the permeation-promoting mechanisms of chitosan and several of its derivatives, including changing the structure of stratum corneum proteins, acting on the tight junction of granular layers, affecting intercellular lipids, and increasing the water content of stratum corneum. These mechanisms are the reason why chitosan and its derivatives can increase the transdermal permeation of drugs. In addition, various transdermal preparations containing chitosan and its derivatives were summarized, and their respective advantages were expounded, including nanoparticles, emulsions, transdermal microneedles, nanocapsules, transdermal patches, transdermal membranes, hydrogels, liposomes, and nano-stents. The purpose of this review is to provide a theoretical basis for the further and wider application of chitosan in transdermal drug delivery systems. In the future, research results of chitosan and its derivatives in transdermal drug delivery need more support from in vivo experiments, as well as good correlation between in vitro and in vivo experiments. In conclusion, the excellent permeability-promoting property, good biocompatibility, and biodegradability of chitosan and its derivatives make them ideal materials for local transdermal drug delivery.

Nanomaterials-based photosensitizers and delivery systems for photodynamic cancer therapy

The increasing cancer morbidity and mortality requires the development of high-efficiency and low-toxicity anticancer approaches. In recent years, photodynamic therapy (PDT) has attracted much attention in cancer therapy due to its non-invasive features and low side effects. Photosensitizer (PS) is one of the key factors of PDT, and its successful delivery largely determines the outcome of PDT. Although a few PS molecules have been approved for clinical use, PDT is still limited by the low stability and poor tumor targeting capacity of PSs. Various nanomaterial systems have shown great potentials in improving PDT, such as metal nanoparticles, graphene-based nanomaterials, liposomes, ROS-sensitive nanocarriers and supramolecular nanomaterials. The small molecular PSs can be loaded in functional nanomaterials to enhance the PS stability and tumor targeted delivery, and some functionalized nanomaterials themselves can be directly used as PSs. Herein, we aim to provide a comprehensive understanding of PDT, and summarize the recent progress of nanomaterials-based PSs and delivery systems in anticancer PDT. In addition, the concerns of nanomaterials-based PDT including low tumor targeting capacity, limited light penetration, hypoxia and nonspecific protein corona formation are discussed. The possible solutions to these concerns are also discussed.

Pelargonidin-3-O-Glucoside Encapsulated Pectin-Chitosan-Nanoliposomes Recovers Palmitic Acid-Induced Hepatocytes Injury

Pelargonidin-3-O-glucoside (Pg) is a well-known anthocyanin derivative possessing potential biological activity. Nonetheless, the bioactivity of Pg is limited due to instability in the physiological environment. Functionalized nanoliposomes using chitosan and/or pectin coating is an excellent carrier system for nanoencapsulation of food bioactive compounds such as Pg. Therefore, this study aimed to investigate the protective effect of Pg-loaded pectin–chitosan coated nanoliposomes against palmitic acid (PA)-induced hepatocytes injury in L02 cells. Firstly, Pg-loaded pectin–chitosan coated nanoliposomes were characterized using the DLS, HPLC, TEM, and cellular uptake study in L02 cells. Thereafter, we assayed the protective effect against PA-induced lipotoxicity, ROS and O₂^•− generation, mitochondrial dysfunction (MMP), and GSH depletion. Results showed that Pg-loaded nanoliposomes significantly reduced the PA-induced L02 cells toxicity via suppressing ROS production, O₂^•− generation, MMP collapse, and GSH reduction, whereas the free-Pg samples were not effective. On the contrary, the chitosan and/or pectin coated nanoliposomes showed higher results compared to coating-free nanoliposomes. Altogether, the results of our study ensured that Pg-loaded pectin–chitosan coated nanoliposomes was capable of reducing PA-induced hepatocytes injury. Thus, pectin–chitosan coated nanoliposomes can be useful for hepatocellular delivery of hydrophilic compounds with greater biological activity.

Advances in Photodynamic Therapy Based on Nanotechnology and Its Application in Skin Cancer

Comprehensive cancer treatments have been widely studied. Traditional treatment methods (e.g., radiotherapy, chemotherapy), despite ablating tumors, inevitably damage normal cells and cause serious complications. Photodynamic therapy (PDT), with its low rate of trauma, accurate targeting, synergism, repeatability, has displayed great advantages in the treatment of tumors. In recent years, nanotech-based PDT has provided a new modality for cancer treatment. Direct modification of PSs by nanotechnology or the delivery of PSs by nanocarriers can improve their targeting, specificity, and PDT efficacy for tumors. In this review, we strive to provide the reader with a comprehensive overview, on various aspects of the types, characteristics, and research progress of photosensitizers and nanomaterials used in PDT. And the application progress and relative limitations of nanotech-PDT in non-melanoma skin cancer and melanoma are also summarized.

Liposomal-Based Formulations: A Path from Basic Research to Temozolomide Delivery Inside Glioblastoma Tissue

Glioblastoma (GBM) is a lethal brain cancer with a very difficult therapeutic approach and ultimately frustrating results. Currently, therapeutic success is mainly limited by the high degree of genetic and phenotypic heterogeneity, the blood brain barrier (BBB), as well as increased drug resistance. Temozolomide (TMZ), a monofunctional alkylating agent, is the first line chemotherapeutic drug for GBM treatment. Yet, the therapeutic efficacy of TMZ suffers from its inability to cross the BBB and very short half-life (~2 h), which requires high doses of this drug for a proper therapeutic effect. Encapsulation in a (nano)carrier is a promising strategy to effectively improve the therapeutic effect of TMZ against GBM. Although research on liposomes as carriers for therapeutic agents is still at an early stage, their integration in GBM treatment has a great potential to advance understanding and treating this disease. In this review, we provide a critical discussion on the preparation methods and physico-chemical properties of liposomes, with a particular emphasis on TMZ-liposomal formulations targeting GBM developed within the last decade. Furthermore, an overview on liposome-based formulations applied to translational oncology and clinical trials formulations in GBM treatment is provided. We emphasize that despite many years of intense research, more careful investigations are still needed to solve the main issues related to the manufacture of reproducible liposomal TMZ formulations for guaranteed translation to the market.

Injectable and Biodegradable Chitosan Hydrogel-Based Drug Depot Contributes to Synergistic Treatment of Tumors

Combined therapy provides a more effective method in the treatment of tumors and becomes a research hotspot. To improve treatment outcomes and reduce serious side effects, hydrogel-based local delivery was developed herein to form a drug depot in suit to eliminate tumors. Indocyanine green and imiquimod were coencapsulated in the novel temperature-sensitive chitosan hydrogel. After intratumoral injection of the hydrogel, indocyanine green that accumulated in the tumor area could induce thermal ablation of primary tumors under laser irradiation. In the presence of imiquimod, the immune effects increased the probability of complete ablation of primary tumors and inhibition of metastases. Combined with cyclophosphamide, the enhanced immunological responses would further inhibit tumors and prolong the survival time. In a word, this work offered an excellent local delivery platform that enabled a remarkable combined antitumor strategy and achieved synergistic therapeutic effects.

Nanoparticle-Based Drug Delivery Systems for Photodynamic Therapy of Metastatic Melanoma: A Review

Metastatic melanoma (MM) is a skin malignancy arising from melanocytes, the incidence of which has been rising in recent years. It poses therapeutic challenges due to its resistance to chemotherapeutic drugs and radiation therapy. Photodynamic therapy (PDT) is an alternative non-invasive modality that requires a photosensitizer (PS), specific wavelength of light, and molecular oxygen. Several studies using conventional PSs have highlighted the need for improved PSs for PDT applications to achieve desired therapeutic outcomes. The incorporation of nanoparticles (NPs) and targeting moieties in PDT have appeared as a promising strategy to circumvent various drawbacks associated with non-specific toxicity, poor water solubility, and low bioavailability of the PSs at targeted tissues. Currently, most studies investigating new developments rely on two-dimensional (2-D) monocultures, which fail to accurately mimic tissue complexity. Therefore, three-dimensional (3-D) cell cultures are ideal models to resemble tumor tissue in terms of architectural and functional properties. This review examines various PS drugs, as well as passive and active targeted PS nanoparticle-mediated platforms for PDT treatment of MM on 2-D and 3-D models. The overall findings of this review concluded that very few PDT studies have been conducted within 3-D models using active PS nanoparticle-mediated platforms, and so require further investigation.