In vitro and in ovo photodynamic efficacy of nebulized curcumin-loaded tetraether lipid liposomes prepared by DC as stable drug delivery system.

Lung cancer is one of the most common causes of high mortality worldwide. Current treatment strategies, e.g., surgery, radiotherapy, chemotherapy, and immunotherapy, insufficiently affect the overall outcome. In this study, we used curcumin as a natural photosensitizer in photodynamic therapy and encapsulated it in liposomes consisting of stabilizing tetraether lipids aiming for a pulmonary drug delivery system against lung cancer. The liposomes with either hydrolyzed glycerol-dialkyl-glycerol tetraether (hGDGT) in different ratios or hydrolyzed glycerol-dialkyl-nonitol tetraether (hGDNT) were prepared by dual centrifugation (DC), an innovative method for liposome preparation. The liposomes' physicochemical characteristics before and after nebulization and other nebulization characteristics confirmed their suitability. Morphological characterization using atomic force and transmission electron microscopy showed proper vesicular structures indicative of liposomes. Qualitative and quantitative uptake of the curcumin-loaded liposomes in lung adenocarcinoma (A549) cells was visualized and proven. Phototoxic effects of the liposomes were detected on A549 cells, showing decreased cell viability. The generation of reactive oxygen species required for PDT and disruption of mitochondrial membrane potential were confirmed. Moreover, the chorioallantoic membrane (CAM) model was used to further evaluate biocompatibility and photodynamic efficacy in a 3D cell culture context. Photodynamic efficacy was assessed by PET/CT after nebulization of the liposomes onto the xenografted tumors on the CAM with subsequent irradiation. The physicochemical properties and the efficacy of tetraether lipid liposomes encapsulating curcumin, especially liposomes containing hGDNT, in 2D and 3D cell cultures seem promising for future PDT usage against lung cancer.

Evaluating the photodynamic efficacy of nebulized curcumin-loaded liposomes prepared by thin-film hydration and dual centrifugation: In vitro and in ovo studies.

Lung cancer, one of the most common causes of high mortality worldwide, still lacks appropriate and convenient treatment options. Photodynamic therapy (PDT) has shown promising results against cancer, especially in recent years. However, pulmonary drug delivery of the predominantly hydrophobic photosensitizers still represents a significant obstacle. Nebulizing DPPC/Cholesterol liposomes loaded with the photosensitizer curcumin via a vibrating mesh nebulizer might overcome current restrictions. In this study, the liposomes were prepared by conventional thin-film hydration and two other methods based on dual centrifugation. The liposomes' physicochemical properties were determined before and after nebulization, showing that liposomes do not undergo any changes. However, morphological characterization of the differently prepared liposomes revealed structural differences between the methods in terms of lamellarity. Internalization of curcumin in lung adenocarcinoma (A549) cells was visualized and quantified. The generation of reactive oxygen species because of the photoreaction was also proven. The photodynamic efficacy of the liposomal formulations was tested against A549 cells. They revealed different phototoxic responses at different radiant exposures. Furthermore, the photodynamic efficacy was investigated after nebulizing curcumin-loaded liposomes onto xenografted tumors on the CAM, followed by irradiation, and evaluated using positron emission tomography/computed tomography and histological analysis. A decrease in tumor metabolism could be observed. Based on the efficacy of curcumin-loaded liposomes in 2D and 3D models, liposomes, especially with prior film formation, can be considered a promising approach for PDT against lung cancer.

Solid Lipid Nanoparticles Containing Dopamine and Grape Seed Extract: Freeze-Drying with Cryoprotection as a Formulation Strategy to Achieve Nasal Powders.

(1) Background: DA-Gelucire® 50/13-based solid lipid nanoparticles (SLNs) administering the neurotransmitter dopamine (DA) and the antioxidant grape-seed-derived proanthocyanidins (grape seed extract, GSE) have been prepared by us in view of a possible application for Parkinson's disease (PD) treatment. To develop powders constituted by such SLNs for nasal administration, herein, two different agents, namely sucrose and methyl-ß-cyclodextrin (Me-ß-CD), were evaluated as cryoprotectants. (2) Methods: SLNs were prepared following the melt homogenization method, and their physicochemical features were investigated by Raman spectroscopy, Scanning Electron Microscopy (SEM), atomic force microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). (3) Results: SLN size and zeta potential values changed according to the type of cryoprotectant and the morphological features investigated by SEM showed that the SLN samples after lyophilization appear as folded sheets with rough surfaces. On the other hand, the AFM visualization of the SLNs showed that their morphology consists of round-shaped particles before and after freeze-drying. XPS showed that when sucrose or Me-ß-CD were not detected on the surface (because they were not allocated on the surface or completely absent in the formulation), then a DA surfacing was observed. In vitro release studies in Simulated Nasal Fluid evidenced that DA release, but not the GSE one, occurred from all the cryoprotected formulations. Finally, sucrose increased the physical stability of SLNs better than Me-ß-CD, whereas RPMI 2650 cell viability was unaffected by SLN-sucrose and slightly reduced by SLN-Me-ß-CD. (4) Conclusions: Sucrose can be considered a promising excipient, eliciting cryoprotection of the investigated SLNs, leading to a powder nasal pharmaceutical dosage form suitable to be handled by PD patients.

Modern Photodynamic Glioblastoma Therapy Using Curcumin- or Parietin-Loaded Lipid Nanoparticles in a CAM Model Study.

Natural photosensitizers, such as curcumin or parietin, play a vital role in photodynamic therapy (PDT), causing a light-mediated reaction that kills cancer cells. PDT is a promising treatment option for glioblastoma, especially when combined with nanoscale drug delivery systems. The curcumin- or parietin-loaded lipid nanoparticles were prepared via dual asymmetric centrifugation and subsequently characterized through physicochemical analyses including dynamic light scattering, laser Doppler velocimetry, and atomic force microscopy. The combination of PDT and lipid nanoparticles has been evaluated in vitro regarding uptake, safety, and efficacy. The extensive and well-vascularized chorioallantois membrane (CAM) of fertilized hen's eggs offers an optimal platform for three-dimensional cell culture, which has been used in this study to evaluate the photodynamic efficacy of lipid nanoparticles against glioblastoma cells. In contrast to other animal models, the CAM model lacks a mature immune system in an early stage, facilitating the growth of xenografts without rejection. Treatment of xenografted U87 glioblastoma cells on CAM was performed to assess the effects on tumor viability, growth, and angiogenesis. The xenografts and the surrounding blood vessels were targeted through topical application, and the effects of photodynamic therapy have been confirmed microscopically and via positron emission tomography and X-ray computed tomography. Finally, the excised xenografts embedded in the CAM were analyzed histologically by hematoxylin and eosin and KI67 staining.

RNAi-Mediated Knockdown of Cottontail Rabbit Papillomavirus Oncogenes Using Low-Toxicity Lipopolyplexes as a Paradigm to Treat Papillomavirus-Associated Cancers.

The cottontail rabbit papillomavirus (CRPV)-associated VX2 carcinoma of the New Zealand White rabbit serves as a model system for human papillomavirus (HPV)-associated head and neck squamous cell carcinomas (HNSCCs). The aim of this study was to evaluate the tumor-inhibiting effect of RNAi-mediated knockdown of the CRPV oncogenes, E6 and E7, using siRNA-loaded lipopolyplexes (LPPs). VX2-carcinoma-derived cells were cultured for up to 150 passages. In addition, CRPV E6 and E7 oncogenes were transiently expressed in COS-7 cells. Efficiency and safety of LPPs were evaluated in both VX2 cells and the COS-7 cell line. Both of these in vitro CRPV systems were validated and characterized by fluorescence microscopy, Western blot, and RT-qPCR. Efficient knockdown of CRPV E6 and E7 was achieved in VX2 cells and COS-7 cells pretransfected with CRPV E6 and E7 expression vectors. Knockdown of CRPV oncogenes in VX2 cells resulted in reduced viability, migration, and proliferation and led to a G0/G1 block in the cell cycle. CRPV E6 and E7 siRNA-loaded LPPs could represent promising therapeutic agents serving as a paradigm for the treatment of papillomavirus-positive cancers and could be of value for the treatment of CRPV-associated diseases in the rabbit such as papillomas and cancers of the skin.

Lipid-Coated Polymeric Nanoparticles for the Photodynamic Therapy of Head and Neck Squamous Cell Carcinomas.

Next to alcohol and tobacco abuse, infection with human papillomaviruses (HPVs) is a major risk factor for developing head and neck squamous cell carcinomas (HNSCCs), leading to 350,000 casualties worldwide each year. Limited therapy options and drug resistance raise the urge for alternative methods such as photodynamic therapy (PDT), a minimally invasive procedure used to treat HNSCC and other cancers. We prepared lipid-coated polymeric nanoparticles encapsulating curcumin as the photosensitizer (CUR-LCNPs). The prepared CUR-LCNPs were in the nanometer range (153.37 ± 1.58 nm) and showed an encapsulation efficiency of 92.69 ± 0.03%. Proper lipid coating was visualized using atomic force microscopy (AFM). The CUR-LCNPs were tested in three HPVpos and three HPVneg HNSCC lines regarding their uptake capabilities and in vitro cell killing capacity, revealing a variable but highly significant tumor cell inhibiting effect in all tested HNSCC cell lines. No significant differences were detected between the HPVpos and HPVneg HNSCC groups (mean IC50: (9.34 ± 4.73 µmol/L vs. 6.88 ± 1.03 µmol/L), suggesting CUR-LCNPs/PDT to be a promising therapeutic option for HNSCC patients independent of their HPV status.

Photoactive Parietin-loaded nanocarriers as an efficient therapeutic platform against triple-negative breast cancer.

The application of photodynamic therapy has become more and more important in combating cancer. However, the high lipophilic nature of most photosensitizers limits their parenteral administration and leads to aggregation in the biological environment. To resolve this problem and deliver a photoactive form, the natural photosensitizer parietin (PTN) was encapsulated in poly(lactic-co-glycolic acid) nanoparticles (PTN NPs) by emulsification diffusion method. PTN NPs displayed a size of 193.70 nm and 157.31 nm, characterized by dynamic light scattering and atomic force microscopy, respectively. As the photoactivity of parietin is essential for therapy, the quantum yield of PTN NPs and the in vitro release were assessed. The antiproliferative activity, the intracellular generation of reactive oxygen species, mitochondrial potential depolarization, and lysosomal membrane permeabilization were evaluated in triple-negative breast cancer cells (MDA-MB-231 cells). At the same time, confocal laser scanning microscopy (CLSM) and flow cytometry were used to investigate the cellular uptake profile. In addition, the chorioallantoic membrane (CAM) was employed to evaluate the antiangiogenic effect microscopically. The spherical monomodal PTN NPs show a quantum yield of 0.4. The biological assessment on MDA-MB-231 cells revealed that free PTN and PTN NPs inhibited cell proliferation with IC50 of 0.95 µM and 1.9 µM at 6 J/cm2, respectively, and this can be attributed to the intracellular uptake profile as proved by flow cytometry. Eventually, the CAM study illustrated that PTN NPs could reduce the number of angiogenic blood vessels and disrupt the vitality of xenografted tumors. In conclusion, PTN NPs are a promising anticancer strategy in vitro and might be a tool for fighting cancer in vivo.

Generation of a Syngeneic Heterozygous ACVRL1(wt/mut) Knockout iPS Cell Line for the In Vitro Study of HHT2-Associated Angiogenesis.

Hereditary hemorrhagic telangiectasia (HHT) type 2 is an autosomal dominant disease in which one allele of the ACVRL1 gene is mutated. Patients exhibit disturbances in TGF-beta/BMP-dependent angiogenesis and, clinically, often present with severe nosebleeds as well as a reduced quality of life. The aim of our study was to use CRISPR/Cas9 to knockout ACVRL1 in normal induced pluripotent stem cells (iPSCs) and evaluate the effects on TGF-beta- and BMP-related gene expression as well as angiogenesis. The CRISPR/Cas9 knockout of the ACVRL1 gene was carried out in previously characterized wild-type (ACVRL1wt/wt) iPSCs. An HHT type 2 iPS cell line was generated via a single-allele knockout (ACVRL1wt/mut) in wild-type (ACVRL1wt/wt) iPSCs, resulting in a heterozygous 17 bp frameshift deletion in the ACVRL1 gene [NG_009549.1:g.13707_13723del; NM_000020.3:c.1137_1153del]. After the generation of embryoid bodies (EBs), endothelial differentiation was induced via adding 4 ng/mL BMP4, 2% B27, and 10 ng/mL VEGF. Endothelial differentiation was monitored via immunocytochemistry. An analysis of 151 TGF-beta/BMP-related genes was performed via RT-qPCR through the use of mRNA derived from single iPS cell cultures as well as endothelial cells derived from EBs after endothelial differentiation. Differential TGF-beta/BMP gene expression was observed between ACVRL1wt/wt and ACVRL1wt/mut iPSCs as well as endothelial cells. EBs derived from CRISPR/Cas9-designed ACVRL1 mutant HHT type 2 iPSCs, together with their isogenic wild-type iPSC counterparts, can serve as valuable resources for HHT type 2 in vitro studies.

How to Xenograft Cancer Cells on the Chorioallantoic Membrane of a Fertilized Hen's Egg and Its Visualization by PET/CT and MRI.

The chorioallantoic membrane (CAM) of fertilized hen's eggs represents a unique and alternative model for cancer research. The CAM model provides an optimal platform for xenografting cancer cell lines and studying essential key factors. Tumor size and growth as well as angiogenesis can be investigated to evaluate the response of therapies and strategies against cancer. Preclinical imaging represented by magnetic resonance imaging and positron emission tomography/computed tomography can generate detailed anatomical and functional information and reveal excellent metabolic sensitivity. In the following, a guideline is introduced in order to find a simplified entrance to the CAM model in combination with modern preclinical imaging techniques. Finally, the presented procedures are additionally completed by histological studies in the form of hematoxylin and eosin as well as immunohistochemical staining.

Co-Delivery of Ylang Ylang Oil of Cananga odorata and Oxaliplatin Using Intelligent pH-Sensitive Lipid-Based Nanovesicles for the Effective Treatment of Triple-Negative Breast Cancer.

Smart pH-responsive niosomes loaded with either Oxaliplatin (Ox), Ylang ylang essential oil (Y-oil), or co-loaded with both compounds (Ox-Y) (Ox@NSs, Y@NSs, and Ox-Y@NSs, respectively) were formulated utilizing the thin film method. The developed nanocontainers had a spherical morphology with mean particle sizes lower than 170 nm and showed negative surface charges, high entrapment efficiencies, and a pH-dependent release over 24 h. The prepared pH-responsive niosomes' cytotoxicity was tested against the invasive triple-negative breast cancer (MDA-MB-231) cells, compared to free OX and Y-oil. All niosomal formulations loaded with Ox and/or Y-oil significantly improved cytotoxic activity relative to their free counterparts. The Ox-Y@NSs demonstrated the lowest IC50 (0.0002 µg/mL) when compared to Ox@NSs (0.006 µg/mL) and Y@NSs (18.39 µg/mL) or unloaded Ox (0.05 µg/mL) and Y-oil (29.01 µg/mL). In addition, the percentages of the MDA-MB-231 cell population in the late apoptotic and necrotic quartiles were profoundly higher in cells treated with the smart Ox-Y@NSs (8.38% and 5.06%) than those exposed to free Ox (7.33% and 1.93%) or Y-oil (2.3% and 2.13%) treatments. Gene expression analysis and protein assays were performed to provide extra elucidation regarding the molecular mechanism by which the prepared pH-sensitive niosomes induce apoptosis. Ox-Y@NSs significantly induced the gene expression of the apoptotic markers Tp53, Bax, and Caspase-7, while downregulating the antiapoptotic Bcl2. As such, Ox-Y@NSs are shown to activate the intrinsic pathway of apoptosis. Moreover, the protein assay ascertained the apoptotic effects of Ox-Y@NSs, generating a 4-fold increase in the relative protein quantity of the late apoptotic marker Caspase-7. Our findings suggest that combining natural essential oil with synthetic platinum-based drugs in pH-responsive nanovesicles is a promising approach to breast cancer therapy.

Magnetic Thermosensitive Liposomes Loaded with Doxorubicin.

Liposome-mediated anticancer drug delivery has the advantage of limiting the massive cytotoxicity of chemotherapeutic agents. Doxorubicin (DOX) PEG-liposomal does however have a slow-release rate that hinders its therapeutic efficacy. In this study, an integrated therapeutic system based on magnetic thermosensitive liposomes was designed. The chelated gadolinium acquired magnetic properties in the liposomes. The hyperthermia induced by ultra-high-field magnetic resonance imaging (UHF-MRI) enhances the chemotherapeutic effects of DOX. The DOX release from liposomes was facilitated over a narrow range of temperatures owing to the phase transition temperature of the liposomes. The magnetic properties of the liposomes were evident by the elevation of contrast after the exposure to UHF-MRI. Moreover, triple-negative breast cancer (TNBC) cells showed a significant decrease in cellular viability reaching less than 40% viability after 1 h of exposure to UHF-MRI. The liposomes demonstrated a physiological coagulation time and a minimal hemolytic potential in hemocompatibility studies; therefore, they were considered safe for physiological application. As a result, magnetic-thermosensitive liposomal guidance of local delivery of DOX could increase the therapeutic index, thereby reducing the amount of the drug required for systemic administration and the chance of affecting the adjacent tissues.

Visualization and Characterization of Liposomes by Atomic Force Microscopy.

Atomic force microscopy is a high-resolution and nonoptical technique used to visualize and characterize biological samples and surfaces. In pharmaceutical research and development (R&D) and quality control (QC), drug delivery systems, like liposomes with sizes in a nanometer range, are preferred samples to be studied through atomic force microscopy. The instrument can determine the sample's topography (e.g., height), morphology, and material properties (e.g., hardness, adhesiveness). Various measuring modes, e.g., intermittent contact (AC mode), can generate height (measured), lock-in amplitude, and lock-in phase data, revealing interesting details about the drug delivery system.In this study, empty and drug-loaded liposomes with various lipid compositions and sizes (50-800 nm) were visualized and characterized with state-of-the-art atomic force microscope (AFM). The main focus here was the preparation methods of the samples, instrumental settings, and pitfalls that can occur during the whole imaging process. Moreover, troubleshooting and postdata processing are essential for a high-quality outcome.

Photothermally Controlled Drug Release of Poly(d,l-lactide) Nanofibers Loaded with Indocyanine Green and Curcumin for Efficient Antimicrobial Photodynamic Therapy.

Chronic wound infections with antibiotic-resistant bacteria have become a significant problem for modern healthcare systems since they are often associated with high costs and require profound topical wound management. Successful wound healing is achieved by reducing the bacterial load of the wound and providing an environment that enhances cell growth. In this context, nanofibers show remarkable success because their structure offers a promising drug delivery platform that can mimic the native extracellular matrix and accelerate cell proliferation. In our study, single-needle electrospinning, a versatile and cost-efficient technique, was used to shape polymers into an applicable and homogeneous fleece capable of a photothermally triggered drug release. It was combined with antimicrobial photodynamic therapy, a promising procedure against resistant bacteria. Therefore, poly(d,l-lactide) nanofibers loaded with curcumin and indocyanine green (ICG) were produced for local antimicrobial treatment. The mesh had a homogeneous structure, and the nanofibers showed a smooth surface. Recordings with a thermal camera showed that near-infrared light irradiation of ICG increased the temperature (>44 °C) in the surrounding medium. Release studies confirmed more than 29% enhanced curcumin release triggered by elevated temperature. The antimicrobial activity was tested against the gram-positive strain Staphylococcus saprophyticus subsp. bovis and the gram-negative strain Escherichia coli DH5 alpha. The nanofibers loaded with both photosensitizers and irradiated with both wavelengths reduced the bacterial viability (~4.4 log10, 99.996%) significantly more than the nanofibers loaded with only one photosensitizer (<1.7 log10, 97.828%) or irradiated with only one wavelength (<2.0 log10, 98.952%). In addition, our formulation efficiently eradicated persistent adhered bacteria by >4.3 log10 (99.995%), which was also confirmed visually. Finally, the produced nanofibers showed good biocompatibility, proven by the cellular viability of mouse fibroblasts (L929). The data demonstrate that we have developed a new economic nanofiber formulation, which offers a triggered drug release, excellent antimicrobial properties, and good biocompatibility.

Recent Innovations of Mesoporous Silica Nanoparticles Combined with Photodynamic Therapy for Improving Cancer Treatment.

Cancer is a global health burden and is one of the leading causes of death. Photodynamic therapy (PDT) is considered an alternative approach to conventional cancer treatment. PDT utilizes a light-sensitive compound, photosensitizers (PSs), light irradiation, and molecular oxygen (O2). This generates cytotoxic reactive oxygen species (ROS), which can trigger necrosis and/ or apoptosis, leading to cancer cell death in the intended tissues. Classical photosensitizers impose limitations that hinder their clinical applications, such as long-term skin photosensitivity, hydrophobic nature, nonspecific targeting, and toxic cumulative effects. Thus, nanotechnology emerged as an unorthodox solution for improving the hydrophilicity and targeting efficiency of PSs. Among nanocarriers, mesoporous silica nanoparticles (MSNs) have gained increasing attention due to their high surface area, defined pore size and structure, ease of surface modification, stable aqueous dispersions, good biocompatibility, and optical transparency, which are vital for PDT. The advancement of integrated MSNs/PDT has led to an inspiring multimodal nanosystem for effectively treating malignancies. This review gives an overview of the main components and mechanisms of the PDT process, the effect of PDT on tumor cells, and the most recent studies that reported the benefits of incorporating PSs into silica nanoparticles and integration with PDT against different cancer cells.

Thermosensitive Liposomes Encapsulating Nedaplatin and Picoplatin Demonstrate Enhanced Cytotoxicity against Breast Cancer Cells.

Thermosensitive liposomes (TSL) have been used for localized temperature-responsive release of chemotherapeutics into solid cancers, with a minimum of one invention currently in clinical trials (phase III). In this study, TSL was designed using a lipid blend comprising 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), cholesterol, and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[maleimide(polyethylene glycol)-2000] (DSPE-PEG-2000) (molar ratio of 88:9:2.8:0.2). Either nedaplatin (ND) or p-sulfonatocalix[4]arene-nedaplatin was encapsulated in the aqueous inner layer of TSL to form (ND-TSL) or p-SC4-ND-TSL, respectively. The hydrophobic platinum-based drug picoplatin (P) was loaded into the external lipid bilayer of the TSL to develop P-TSL. The three nanosystems were studied in terms of size, PDI, surface charge, and on-shelf stability. Moreover, the entrapment efficiency (EE%) and release % at 37 and 40 °C were evaluated. In a 30 min in vitro release study, the maximum release of ND, p-SC4-ND, and picoplatin at 40 °C reached 74, 79, and 75%, respectively, compared to approximately 10% at 37 °C. This demonstrated temperature-triggered drug release from the TSL in all three developed systems. The designed TSL exhibited significant in vitro anticancer activity at 40 °C when tested on human mammary gland/breast adenocarcinoma cells (MDA-MB-231). The cytotoxicity of ND-TSL, p-SC4-ND-TSL, and P-TSL at 40 °C was approximately twice those observed at 37 °C. This study suggests that TSL is a promising nanoplatform for the temperature-triggered release of platinum-based drugs into cancer cells.

Highly Stable Liposomes Based on Tetraether Lipids as a Promising and Versatile Drug Delivery System.

Conventional liposomes often lack stability, limiting their applicability and usage apart from intravenous routes. Nevertheless, their advantages in drug encapsulation and physicochemical properties might be helpful in oral and pulmonary drug delivery. This study investigated the feasibility and stability of liposomes containing tetraether lipids (TEL) from Thermoplasma acidophilum. Liposomes composed of different molar ratios of TEL:Phospholipon 100H (Ph) were produced and exposed to various temperature and pH conditions. The effects on size, polydispersity index, and zeta potential were examined by dynamic and electrophoretic light scattering. Autoclaving, which was considered an additional process step after fabrication, could minimize contamination and prolong shelf life, and the stability after autoclaving was tested. Moreover, 5(6)-carboxyfluorescein leakage was measured after incubation in the presence of fetal calf serum (FCS) and lung surfactant (Alveofact). The incorporation of TEL into the liposomes significantly impacted the stability against low pH, higher temperatures, and even sterilization by autoclaving. The stability of liposomes containing TEL was confirmed by atomic force microscopy as images revealed similar sizes and morphology before and after incubation with FCS. It could be concluded that increasing the molar ratio in the TEL:Ph liposome formulations improved the structural stability against high temperature, low pH, sterilization via autoclaving, and the presence of FCS and lung surfactant.

Liposome-Encapsulated Bioactive Guttiferone E Exhibits Anti-Inflammatory Effect in Lipopolysaccharide-Stimulated MH-S Macrophages and Cytotoxicity against Human Cancer Cells.

Background: Guttiferone E is a naturally occurring polyisoprenylated benzophenone exhibiting a wide range of remarkable biological activities. But its therapeutic application is still limited due to its poor water solubility. This study is aimed at preparing guttiferone E-loaded liposomes and assessing their in vitro cytotoxicity and anti-inflammatory effect. Methods: Liposomes containing guttiferone E were prepared by the thin film hydration method, and the physicochemical characteristics were determined using dynamic light scattering, laser Doppler velocimetry, and atomic force microscopy. The cytotoxicity was assessed by the MTT assay. The fluorometric cyclooxygenase (COX) activity assay kit was used to assess the COX activity while the nitric oxide production was evaluated by the Griess reagent method. Results: The liposomes with a mean size of 183.33 ± 17.28 nm were obtained with an entrapment efficiency of 63.86%. Guttiferone E-loaded liposomes successfully decreased the viability of cancer cells. The overall IC50 values varied between 5.46 µg/mL and 22.25 µg/mL. Compared to the untreated control, guttiferone E-loaded liposomes significantly reduced the nitric oxide production and the activity of COX in a concentration-dependent manner. Conclusion: This study indicates that liposomes can be an alternative to overcome the water insolubility issue of the bioactive guttiferone E.

Editorial on the "Special Issue in Honor of Dr. Michael Weber's 70th Birthday: Photodynamic Therapy: Rising Star in Pharmaceutical Applications".

Thousands of years ago, phototherapy or heliotherapy was performed by ancient Egyptians, Greeks, and Romans [...].

Co-delivery of carbonic anhydrase IX inhibitor and doxorubicin as a promising approach to address hypoxia-induced chemoresistance.

Hypoxia, an oxygen-deprived condition of the tumor, is one of the major reasons for resistance to chemotherapy. Carbonic anhydrases are generally involved in pH homeostasis in normal conditions, but in solid tumors having a strong relation with hypoxia, the carbonic anhydrase IX (CA-IX) enzyme is overexpressed and results in an extracellular acidic environment. For most weakly basic anticancer drugs, including doxorubicin (Dox), the ionization in an acidic environment limits their cellular uptake, and consequently, the tumor exposure to the drug at sub-therapeutic concentration comes out as chemoresistance. Herein, a combined drug delivery system of liposomes and mesoporous silica nanoparticles (MSNPs) was developed for the co-delivery of the CA-IX enzyme inhibitor and Dox in hypoxic condition. The unique structure of MSNPs with higher surface area was utilized for higher drug loading and sustained release of Dox. Additionally, the biocompatible nature of liposomal coating as a second loading site for the CA-IX enzyme inhibitor has provided gatekeeping effects at pore opening to avoid premature drug release. Lipid coated MSNPs as a co-delivery system for Dox and the CA-IX inhibitor have synergistic cytotoxic effects against MDA-MB 231 breast cancer cells in hypoxic conditions. These findings assure the potential of this drug delivery system to overcome hypoxia-related chemoresistance.