Study on docetaxel-loaded nanoparticles with high antitumor efficacy against malignant melanoma

Functionalization of Nanomaterials for Skin Cancer Theranostics

Skin cancer has drawn attention for the increasing incident rates and high morbidity worldwide. Timely diagnosis and efficient treatment are of paramount importance for prompt and effective therapy. Thus, the development of novel skin cancer diagnosis and treatment strategies is of great significance for both fundamental research and clinical practice. Recently, the emerging field of nanotechnology has profoundly impact on early diagnosis and better treatment planning of skin cancer. In this review, we will discuss the current encouraging advances in functional nanomaterials for skin cancer theranostics. Challenges in the field and safety concerns of nanomaterials will also be discussed.

Recent Advances in the Local Drug Delivery Systems for Improvement of Anticancer Therapy

The conventional anticancer chemotherapies not only cause serious toxic effects, but also produce resistance in tumor cells exposed to long-term therapy. Usually, the killing of metastasized cancer cells requires long-term therapy with higher drug doses, because the cancer cells develop resistance due to the induction of poly-glycoproteins (P-gps) that act as a transmembrane efflux pump to transport drugs out of the cells. During the last few decades, scientists have been exploring new anticancer drug delivery systems such as microencapsulation, hydrogels, and nanotubes to improve bioavailability, reduce drug-dose requirement, decrease multiple drug resistance, and to save normal cells as non-specific targets. Hopefully, the development of novel drug delivery vehicles (nanotubes, liposomes, supramolecules, hydrogels, and micelles) will assist to deliver drug molecules at the specific target site and reduce the undesirable side effects of anticancer therapies in humans. Nanoparticles and lipid formulations are also designed to deliver small drug payload at the desired tumor cell sites for their anticancer actions. This review will focus on the recent advances in the drug delivery systems, and their application in treating different cancer types in humans.

Self-assembled tacrolimus-loaded lecithin-chitosan hybrid nanoparticles for in vivo management of psoriasis

Lecithin-chitosan hybrid nanoparticles are emerging as a promising nanocarrier for topical drug delivery. They could achieve a maximized encapsulation of hydrophobic drugs due to the lipophilic nature of lecithin that comprises the core while enhancing retention in the upper skin layers using the positively charged polymeric coat of chitosan. The aim of this study is to incorporate tacrolimus; a hydrophobic anti-proliferative agent into lecithin chitosan hybrid nanoparticles by ethanolic injection technique using a suitable co-solvent to enhance encapsulation of the drug and allow a satisfactory release profile in the upper skin layers. Tacrolimus was successfully incorporated into the synthesized particles using olive oil and Tween 80 as co-solvents, with particle size (160.9 nm ± 15.9 and 118.7 nm ± 13.3, respectively) and EE (88.27% ± 4.3 and 66.72% ± 1.8, respectively). The in vitro drug release profile showed a faster release pattern for the Tween 80-containing particles over a 48-hour period (79.98% vs. 35.57%), hence, were selected for further investigation. The hybrid nanoparticles achieved significantly higher skin deposition than the marketed product (63.51% vs. 34.07%) through a 24-hour time interval, particularly, to the stratum corneum and epidermis skin layers. The in vivo results on IMQ-mouse models revealed superior anti-psoriatic efficacy of the synthesized nanoparticles in comparison to the marketed product in terms of visual observation of the skin condition, PASI score and histopathological examination of autopsy skin samples. Additionally, the in vivo drug deposition showed superior skin deposition of the nanoparticles compared to the marketed product (74.9% vs. 13.4%).

Tacrolimus-loaded chitosan nanoparticles for enhanced skin deposition and management of plaque psoriasis

Tacrolimus is a natural macrolide that exhibits an anti-proliferative action by T-lymphocytic cells inhibition. Hence, it was tested as a potential topical treatment to improve and control psoriatic plaques. In this study, for the first time the lipophilic tacrolimus in chitosan nanoparticles was used to achieve the desired response and dermal retention of the drug using a modified ionic gelation technique. The hydrophobic drug, tacrolimus, was successfully encapsulated into the synthesized positively-charged particles (140.8 nm ± 50.0) and EE of (65.5% ± 1.3). Local skin deposition of the drug was significantly enhanced with 82.0% ± 0.6 of the drug retained in the skin compared to 34.0% ± 0.9 from tarolimus® ointment. An outstanding response to the prepared formula was the enhanced hair growth rate in the treated animals, which can be considered an excellent sign of the skin recovery from the induced psoriatic plaques after only three days of treatment.

Recent Advances in Nanotechnology for the Treatment of Melanoma

Melanoma is one of the most aggressive forms of skin cancer, with few possibilities for therapeutic approaches, due to its multi-drug resistance and, consequently, low survival rate for patients. Conventional therapies for treatment melanoma include radiotherapy, chemotherapy, targeted therapy, and immunotherapy, which have various side effects. For this reason, in recent years, pharmaceutical and biomedical research has focused on new sito-specific alternative therapeutic strategies. In this regard, nanotechnology offers numerous benefits which could improve the life expectancy of melanoma patients with very low adverse effects. This review aims to examine the latest advances in nanotechnology as an innovative strategy for treating melanoma. In particular, the use of different types of nanoparticles, such as vesicles, polymers, metal-based, carbon nanotubes, dendrimers, solid lipid, microneedles, and their combination with immunotherapies and vaccines will be discussed.

Preparation, optimization, and in-vitro characterization of α-tocopherol-loaded solid lipid nanoparticles (SLNs)

Objective: The main scope of present investigation was preparation and physicochemical characterization of solid lipid nanoparticles (SLNs) loaded by α-tocopherol acetate (ATA).Methods: ATA-loaded nanoparticles were prepared by solvent injection-homogenization technique using stearic acid as the solid lipid, phosphatidylcholine as the stabilizer and finally coated by chitosan with the aim of increasing z-potential and also having a more stable nano-formulation. Then, characterization of SLNs has been conducted using dynamic light scattering (DLS), zeta potential measurement, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC).Results: Nanoparticles with average sizes of 175 ± 15 nm and zeta potential of +35 ± 2.5 mV were obtained. An excellent drug entrapment efficiency of 90.58 ± 1.38% was obtained with a no-burst slow release up to about 10 days tested. The final plateau of release of ATA from nanoparticulate system within 216 h was 61.13 ± 0.13% which was approached in about 150 h. Physical stability studies showed that the ATA nano-formulation remained stable with slight increase in mean particle size and polydispersity index over a 3-month period in refrigerated temperature. Considering both FTIR and DSC analysis, it can be concluded that there is no new band formation between materials and ATA in our nano-formulation. Particle sizes obtained using AFM images are in a good agreement to those established from the DLS analysis.Conclusion: These data showed a promising delivery system for vitamin E based on SLN platform.

Enhancement in Site-Specific Delivery of Carvacrol against Methicillin Resistant Staphylococcus aureus Induced Skin Infections Using Enzyme Responsive Nanoparticles: A Proof of Concept Study

Methicillin resistant Staphylococcus aureus (MRSA) induced skin infections have become a challenging problem due to the escalating antibiotic resistance. Carvacrol (CAR) has been reported to be effective against MRSA. However, due to its characteristics, CAR exhibits low skin retention. In this study, CAR was formulated into site-specific nanoparticle (NPs) delivery system using poly(ε-caprolactone) (PCL), following incorporation into a hydrogel matrix to facilitate dermal delivery. The release study exhibited significantly higher release of CAR from PCL NPs in the presence of bacterial lipase, highlighting its potential for differential delivery. Moreover, encapsulation of CAR in PCL NPs resulted in a two-fold increase in its anti-MRSA activity. Dermatokinetic studies revealed that the NPs loaded hydrogel was able to enhance skin retention of CAR after 24 h (83.29 ± 3.15%), compared to free CAR-loaded hydrogel (0.85 ± 0.14%). Importantly, this novel approach exhibited effective antimicrobial activity in an ex-vivo skin infection model. Hence, these findings have proven the concept that the loading of CAR into a responsive NPs system can lead to sustained antimicrobial effect at the desired site, and may provide a novel effective approach for treatment of MRSA induced skin infections. However, further studies must be conducted to investigate in-vivo efficacy of the developed system in an appropriate infection model.

Enhancing the Delivery of Chemotherapeutics: Role of Biodegradable Polymeric Nanoparticles

While pharmaceutical drugs have revolutionized human life, there are several features that limit their full potential. This review draws attention to some of the obstacles currently facing the use of chemotherapeutic drugs including low solubility, poor bioavailability and high drug dose. Overcoming these issues will further enhance the applicability and potential of current drugs. An emerging technology that is geared towards improving overall therapeutic efficiency resides in drug delivery systems including the use of polymeric nanoparticles which have found widespread use in cancer therapeutics. These polymeric nanoparticles can provide targeted drug delivery, increase the circulation time in the body, reduce the therapeutic indices with minimal side-effects, and accumulate in cells without activating the mononuclear phagocyte system (MPS). Given the inroads made in the field of nanodelivery systems for pharmaceutical applications, it is of interest to review and emphasize the importance of Polymeric nanocarrier system for drug delivery in chemotherapy.

Berberine nanoparticles protects tubular epithelial cells from renal ischemia-reperfusion injury

Renal ischemia-reperfusion (I/R) injury is one of the most common causes of acute renal failure, the prognosis of which remains poor and there still lacks of effective therapeutics available in the clinic. This study aimed at investigating the effects of Berberine nanoparticles (BBR-NP) on the ischemia-reperfusion injury of renal tubular epithelial cells and underlying the mechanisms. Our results showed that in a rat model of renal I/R injury, BBR and BBR-NP protected renal against injury both functionally (as assessed by serum urea nitrogen and creatinine level) and morphologically (as assessed by HE staining, transmission electron microscopy and TUNEL staining) in a dose-dependent manner, with the effects of BBR-NP superior to BBR alone. Mechanism investigation showed that BBR-NP reversed oxidative stress and subsequent apoptosis of renal cells, as demonstrated by the decreased expression of proteins involved in the oxidative stress and mitochondrial stress pathways. In conclusion, our study showed that BBR-NP is superior to BBR alone in protecting renal against I/R injury and explored the underlying mechanisms, which should be tested in further studies and might give impetus to the development of novel therapeutics based on BBR-NP against renal I/R.

Co-delivery of doxorubicin and pheophorbide A by pluronic F127 micelles for chemo-photodynamic combination therapy of melanoma

In this work, doxorubicin (DOX)-loaded pheophorbide A (PheoA) modified Pluronic F127 (F127) micelles (DOX/F127-PheoA micelles) were developed for combined chemo-photodynamic therapy of melanoma.

In-vitro cytotoxicity and combination effects of the docetaxel-conjugated and doxorubicin-conjugated poly(lactic acid)-poly(ethylene glycol)-folate-based polymeric micelles in human ovarian cancer cells

OBJECTIVES

The pH-sensitive doxorubicin (DOX)-conjugated and docetaxel (DTX)-conjugated poly(lactic acid)-poly(ethylene glycol)-folate (PLA-PEG-FOL)-based polymeric micelles were developed and characterized in this study.

KEY FINDINGS

The drugs were released from the micelles (particle size, ~185 nm) in a pH-dependent manner. The drug-conjugated PLA-PEG-FOL micelles showed higher cellular uptake than nontargeting ones. Single agent and combination in-vitro cytotoxicity studies were also performed using the two drugs in both free and their micellar forms in SKOV3 human ovarian cancer cells using three different cytotoxicity assays. Like the free drugs, DOX-conjugated and DTX-conjugated targeting micelles showed significant cytotoxic effects in SKOV3 cell line. Moreover, the drug-conjugated targeting micelles improved cytotoxicity compared to the FOL-free ones. Different ratios of IC₅₀ of free drugs were used for combination therapy, and synergistic, additive or antagonistic effects were evaluated. The synergistic effect was observed in specific DOX : DTX mixing ratios, which result in the increase in therapeutic efficacy using low doses of each test compound without formulation related side effects.

CONCLUSIONS

The prepared micelles may provide appropriate delivery systems for doxorubicin and docetaxel in both single and combination therapies.

Cationic PEGylated polycaprolactone nanoparticles carrying post-operation docetaxel for glioma treatment

Background: Brain tumors are the most common tumors among adolescents. Although some chemotherapeutics are known to be effective against brain tumors based on cell culture studies, the same effect is not observed in clinical trials. For this reason, the development of drug delivery systems is important to treat brain tumors and prevent tumor recurrence. The aim of this study was to develop core-shell polymeric nanoparticles with positive charge by employing a chitosan coating. Additionally, an implantable formulation for the chemotherapeutic nanoparticles was developed as a bioadhesive film to be applied at the tumor site following surgical operation for brain glioma treatment. To obtain positively charged, implantable nanoparticles, the effects of preparation technique, chitosan coating concentration and presence of surfactants were evaluated to obtain optimal nanoparticles with a diameter of less than 100 nm and a net positive surface charge to facilitate cellular internalization of drug-loaded nanoparticles. Hydroxypropyl cellulose films were prepared to incorporate these nanoparticle dispersions to complete the implantable drug delivery system. Results: The diameter of core-shell nanoparticles were in the range of 70-270 nm, depending on the preparation technique, polymer type and coating. Moreover, the chitosan coating significantly altered the surface charge of the nanoparticles to net positive values of +30 to +50 mV. The model drug docetaxel was successfully loaded into all particles, and the drug release rate from the nanoparticles was slowed down to 48 h by dispersing the nanoparticles in a hydroxypropyl cellulose film. Cell culture studies revealed that docetaxel-loaded nanoparticles cause higher cytotoxicity compared to the free docetaxel solution in DMSO. Conclusion: Docetaxel-loaded nanoparticles dispersed in a bioadhesive film were shown to be suitable for application of chemotherapeutics directly to the action site during surgical operation. The system was found to release chemotherapeutics for several days at the tumor site and neighboring tissue. This can be suggested to result in a more effective brain tumor treatment when compared to chemotherapeutics administered as an intravenous bolus infusion.

Pluronic F68-Linoleic Acid Nano-spheres Mediated Delivery of Gambogic Acid for Cancer Therapy

Gambogic acid (GA), a natural compound from gamboge resin, has been introduced as a promising antitumor drug contributing to its broad spectrum of antitumor activity. However, the poor aqueous solubility and short half-life hinder its clinical application. Pluronic F68 (F68) is a well-known amphiphilic block copolymer consisting of hydrophobic propylene oxide units and hydrophilic ethylene oxide. Although F68 has an amphiphilic structure, its short propylene oxide segment limits its dilution stability and drug-loading capacity. To overcome this limitation, we modified F68 by conjugating linoleic acid, a hydrophobic fatty acid, to increase the hydrophilic-hydrophobic interaction and thus improve the stability of F68 nano-spheres. This F68-linoleic acid (F68-LA) conjugate was synthesized and was used to load GA to improve its anticancer effects. GA-loaded F68-LA nano-spheres were stable for 6 days, with a mean diameter of 159.3 nm and zeta potential of -23.2 mV. The entrapment efficiency of GA in F68-LA nano-spheres was as high as 92.0%. Furthermore, F68-LA/GA nano-spheres exhibited an enhanced cytotoxic activity and proapoptotic effect against human ovarian cancer A2780 cells, compared with free GA. Our results showed that the F68-LA/GA nano-spheres might be a promising cancer-targeted drug delivery system in ovarian cancer therapy.

α-Tocopheryl linolenate solid lipid nanoparticles for the encapsulation, protection, and release of the omega-3 polyunsaturated fatty acid: in vitro anti-melanoma activity evaluation

The main target of this study was the preparation, characterization and antioxidant activity evaluation of α-tocopheryl linolenate based solid lipid nanoparticles (SLNs-TL), able to incorporate omega-3 α-linolenic acid, useful for the treatment of melanoma, a type of skin cancer. In particular, α-linolenic acid was successfully derivatized with α-tocopherol and the obtained compound was characterized by Fourier transform infrared (FT-IR) and by ¹H NMR to confirm the ester linkage. Both the empty SLNs-TL that SLNs-TL-LIN, containing omega-3-linolenic acid, were prepared through the technique of the microemulsion. The nanoparticles were characterized for entrapment efficiency, size and shape. Their antioxidant activity was investigated in rat liver microsomal membranes in inhibiting the lipid peroxidation induced by tert-butyl hydroperoxide (tert-BOOH), which endogenously produces alkoxyl radicals by Fenton reactions. The obtained results indicate that the α-tocopherol, linked by ester bond to α-linolenic acid, maintains an excellent antioxidant activity. The encapsulation efficiency was equal to 77% and the polydispersity index 0.198 indicating a good dimensional distribution. Furthermore, the nanoparticles were tested in vitro for their cytotoxic activity against human melanoma cancer cell line C32. Both empty SLNs-TL and loaded SLNs-TL-LIN showed a high biological activity, being more effective than α-linolenic acid and α-tocopherol. The results indicated that these nanoparticles could provide the delivery and the protection of unstable molecules, such as α-linolenic acid, from degradation induced by mechanisms of oxidative stress.

Radiosensitization of TPGS-emulsified docetaxel-loaded poly(lactic-co-glycolic acid) nanoparticles in CNE-1 and A549 cells

Docetaxel is among the most effective radiosensitizers. It is widely used as radiosensitizer in many tumors, including head and neck carcinoma. Nevertheless, poor solubility and severe hypersensitivity limit its clinical use and its therapeutic effect remains to be improved. In this study, docetaxel-loaded polymeric nanoparticles were prepared by nanoprecipitation method to be new radiosensitizer with lower side effects and higher efficacy. The physiochemical characteristics of the nanoparticles were studied. Two human tumor cell lines which are resistant to radiotherapy were used in this research. We have compared the radioenhancement efficacy of docetaxel-loaded nanoparticles with docetaxel in A549 and CNE-1 cells. Compared with docetaxel, radiosensitization of docetaxel-loaded nanoparticles was improved significantly (sensitization enhancement ratio in A549 increased 1.24-fold to 1.68-fold when the radiation was applied 2 h after the drug, p < 0.01, sensitization enhancement ratio in CNE-1 increased 1.32-fold to 1.61-fold, p < 0.05). We explored the mechanisms for the radiosensitization efficiency and the difference between docetaxel and docetaxel-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles. The improved radiosensitization efficacy was associated with enhanced G2/M arrest, promoted apoptosis and the role of D-alpha-tocopheryl polyethylene glycol 1000 succinate which will enhance the cell uptake and inhibit the multiple drug resistance. Moreover, the radiosensitization efficacy of docetaxel-loaded nanoparticles was more prominent than docetaxel. In conclusion, tocopheryl polyethylene glycol 1000 succinate-emulsified docetaxel-loaded PLGA nanoparticles were more efficacious and fewer adverse effects were observed than with the commercial docetaxel formulation. Thus, PLGA nanoparticles hold promise as a radiosensitizing agent.

Synthesis, characterization and anti-cancer activity of Pluronic F68-curcumin conjugate micelles

Curcumin (CUR), a nontoxic polyphenol derived from the rhizome of turmeric (Curcuma longa), has been recognized as an anti-cancer and chemo-preventative agent. However, its clinical application for cancer treatment has been greatly limited due to its poor water-solubility and low bioavailability. To tackle this problem, Pluronic F68-CUR (F68-CUR) conjugate micelles, which are amphiphilic copolymers, were designed and synthesized in this study. These highly stable micelles with CUR concentrated in the core were formulated using the solvent evaporation method and were confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. Physicochemical characterization of F68-CUR conjugate micelles revealed that high drug loading content (DL%; 0.248 mg CUR/1 mg F68) was achieved, and the average particle size of micelles was 115.2 ± 3.0 nm. Compared with free CUR, a significantly higher cytotoxicity against human breast cancer cell line MDA-MB-231 was observed in F68-CUR conjugate micelles. The IC₅₀ value of F68-CUR conjugate micelles was 1.95-fold lower than that of free CUR, indicating that the anti-cancer activity of CUR was significantly improved in the micelles. Furthermore, apoptotic studies demonstrated that F68-CUR conjugate micelles induced more cell apoptosis than that of free CUR. Taken together, these results demonstrate that F68-CUR conjugate micelles are promising to improve the clinical effectiveness of CUR in cancer treatment.

Exploratory use of docetaxel loaded acid-prepared mesoporous spheres for the treatment of malignant melanoma

Introduction

Five year survival for metastatic melanoma (MM) is very low at <10%. Therapeutic options have been limited secondary to systemic toxicity. As a result there has been a growing movement towards developing targeted drug delivery models. Prior research of this group has demonstrated the effectiveness of acid-prepared mesoporous spheres (APMS-TEG) in delivering chemotherapeutic agents at a lower effective dose than systemic administration. This study aims to assess the ability of the previously developed APMS-TEG particles to deliver therapeutic doses of docetaxel for the treatment of melanoma.

Methods

In vitro experiments were performed to assess docetaxel loading onto APMS-TEG particles and release kinetics. Toxicity experiments were performed using docetaxel and docetaxel loaded APMS-TEG. The effect on cell growth was assessed using the MelJuSo, UACC903, and WM1205 melanoma cell lines.

Results

Docetaxel demonstrated statistically significant dose dependent reduction in growth of melanoma cells. In all three cell lines, doses of 1 nM were sufficient to produce statistically significant reduction in cell growth. Scanning electron micrographs demonstrate increased uptake of APMS-TEG particles by melanoma cells in the first 24 hours, with the majority within the first 4 hours. Unloaded APMS particles had no effect on the melanoma cells, demonstrating that the particles themselves are not toxic. APMS-TEG particles had a peak release of drug within the first hour, with equilibration thereafter. The 5, 10, and 20 nM loaded particles all had statistically significant reduction in cell growth than the control groups.

Discussion

The high potency against melanoma cells makes docetaxel a suitable choice for loading into APMS-TEG particles. Docetaxel loaded APMS-TEG particles demonstrate significant activity against malignant melanoma and thus offer an innovative approach to the treatment of metastatic melanoma.

Stimuli responsive drug delivery application of polymer and silica in biomedicine

In the last decade, using polymer and mesoporous silica materials as efficient drug delivery carriers has attracted great attention.

Conjugation of pH-responsive nanoparticles to neural stem cells improves intratumoral therapy

Intratumoral drug delivery is an inherently appealing approach for concentrating toxic chemotherapies at the site of action. This mode of administration is currently used in a number of clinical treatments such as neoadjuvant, adjuvant, and even standalone therapies when radiation and surgery are not possible. However, even when injected locally, it is difficult to achieve efficient distribution of chemotherapeutics throughout the tumor. This is primarily attributed to the high interstitial pressure which results in gradients that drive fluid away from the tumor center. The stiff extracellular matrix also limits drug penetration throughout the tumor. We have previously shown that neural stem cells can penetrate tumor interstitium, actively migrating even to hypoxic tumor cores. When used to deliver therapeutics, these migratory neural stem cells result in dramatically enhanced tumor coverage relative to conventional delivery approaches. We recently showed that neural stem cells maintain their tumor tropic properties when surface-conjugated to nanoparticles. Here we demonstrate that this hybrid delivery system can be used to improve the efficacy of docetaxel-loaded nanoparticles when administered intratumorally. This was achieved by conjugating drug-loaded nanoparticles to the surface of neural stem cells using a bond that allows the stem cells to efficiently distribute nanoparticles throughout the tumor before releasing the drug for uptake by tumor cells. The modular nature of this system suggests that it could be used to improve the efficacy of many chemotherapy drugs after intratumoral administration.

The scope of nanoparticle therapies for future metastatic melanoma treatment

Metastatic melanoma is a highly aggressive malignancy that has traditionally been very difficult to treat. However, after decades of basic research into the signal transduction pathways that promote cancer cell survival, chemoresistance, growth, and crosstalk with the immune system, targeted therapies have now been developed that offer improved survival for patients with metastatic melanoma. Some of the most promising therapies that have been developed include ipilimumab, an anti-cytotoxic T lymphocyte antigen 4 antibody that enhances T-cell activity in the tumour, and selective BRAF inhibitors, such as vemurafenib that blocks tumour cell proliferation in patients with activating BRAF mutations. Although these treatments offer substantial hope for patients, they are not without their drawbacks, which include adverse side-effects, drug resistance, and eventual relapse. Nanotherapeutics holds significant promise to circumvent these shortcomings and has the additional advantage of potentially functioning as a diagnostic device. We will discuss the scope of the use of such multimodal nanoparticles for melanoma treatment and ask whether such particles can offer patients with metastatic melanoma improved prognoses for the future.

Pluronic P105/F127 mixed micelles for the delivery of docetaxel against Taxol-resistant non-small cell lung cancer: optimization and in vitro, in vivo evaluation

The aim of this work was to establish a novel polymeric mixed micelle composed of Pluronic P105 and F127 copolymers loaded with the poorly soluble antitumor drug docetaxel (DTX) against Taxol-resistant non-small cell lung cancer. A central composite design was utilized to optimize the preparation process, helping to improve drug solubilization efficiency and micelle stability. Prepared by a thin-film hydration method, the average size of the optimized mixed micelle was 23 nm, with a 92.40% encapsulation ratio and a 1.81% drug-loading efficiency. The optimized formulation showed high storage stability in lyophilized form, with 95.7% of the drug content remaining after 6 months’ storage at 4°C. The in vitro cytotoxicity assay showed that the IC50 values for Taxotere^® and mixed micelles were similar for A549, while on A549/Taxol cell lines, DTX-loaded P105/F127 mixed micelles showed a superior hypersensitizing effect; their IC50 value (0.059 μg/mL) was greatly reduced compared to those of Taxotere injections (0.593 μg/mL). The in vivo pharmacokinetic study showed that the mixed-micelle formulation achieved a 1.85-fold longer mean residence time in circulation and a 3.82-fold larger area under the plasma concentration-time curve than Taxotere. In addition, therapeutic improvement of mixed micelles in vivo against A549/Taxol was obtained. The tumor inhibition rate of the micelles was 69.05%, versus 34.43% for Taxotere (P < 0.01). Therefore, it could be concluded from the results that DTX-loaded P105/F127 mixed micelles might serve as a potential antitumor drug delivery system to overcome multidrug resistance in lung cancer.

Development and evaluation of 5-fluorouracil loaded chitin nanogels for treatment of skin cancer

This study focuses on development and evaluation of 5-fluorouracil (5-FU) loaded chitin nanogels (FCNGs). It formed good, stable aqueous dispersion with spherical particles in 120-140 nm size range and showed pH responsive swelling and drug release. The FCNGs showed toxicity on melanoma (A375) in a concentration range of 0.4-2.0mg/mL, but less toxicity toward human dermal fibroblast (HDF) cells by MTT assay. Confocal analysis revealed uptake of FCNGs by both cells. From skin permeation experiments, FCNGs showed almost same steady state flux as that of control 5-FU but the retention in the deeper layers of skin was found to be 4-5 times more from FCNGs. Histopathological evaluation revealed loosening of the horny layer of epidermis by interaction of cationically charged chitin, with no observed signs of inflammation and so FCNGs can be a good option for treatment of skin cancers.

Folate-targeted docetaxel-lipid-based-nanosuspensions for active-targeted cancer therapy

The purpose of this study was to develop two novel drug delivery systems based on biodegradable docetaxel-lipid-based-nanosuspensions. The first one was poly(ethylene glycol)- modified docetaxel-lipid-based-nanosuspensions (pLNS). It was developed to increase the cycle time of the drug within the body and enhance the accumulation of the drug at the tumor site. The second one was targeted docetaxel-lipid-based-nanosuspensions (tLNS) using folate as the target ligand. The tLNS could target the tumor cells that overexpressed folate receptor (FR). The morphology, particle size, and zeta potential of pLNS and tLNS were characterized, respectively. The in vitro cytotoxicity evaluation of Duopafei^®, pLNS, and tLNS were performed in human hepatocellular liver carcinoma HepG2 (FR−) and B16 (FR+) cells, respectively. The in vivo antitumor efficacy and pharmacokinetics, as well as the drug tissue distribution, were evaluated in Kunming mice bearing B16 cells. The particle size of pLNS was 204.2 ± 6.18 nm and tLNS had a mean particle size of 220.6 ± 9.54 nm. Cytotoxicity of tLNS against B16 (FR+) cell lines was superior to pLNS (P < 0.05), while there was no significant difference in the half maximum inhibitory concentration values for HepG2 (FR−) cells between pLNS and tLNS. The results of the in vivo antitumor efficacy evaluation showed that tLNS exhibited higher antitumor efficacy by reducing tumor volume (P < 0.01) compared with Duopafei and pLNS, respectively. The results of the in vivo biodistribution study indicate that the better antitumor efficacy of tLNS was attributed to the increased accumulation of the drug in the tumor.

Polycaprolactone microspheres as carriers for dry powder inhalers: effect of surface coating on aerosolization of salbutamol sulfate

This study reports the factors controlling aerosolization of salbutamol sulfate (SS) from mixtures with polycaprolactone (PCL) microspheres fabricated using an emulsion technique with polyvinyl alcohol (PVA) as stabilizer. The fine particle fraction (FPF) of SS from PCL measured by a twin-stage impinger was unexpectedly found to be zero, although scanning electron microscopy showed that the drug coated the entire microsphere. Precoating the microspheres with magnesium stearate (MgSt) excipient solutions (1%-2%) significantly increased (p < 0.05, n = 5) the FPF of SS (11.4%-15.4%), whereas precoating with leucine had a similar effect (FPF = 11.3 ± 1.1%), but was independent of the solution concentration. The force of adhesion (by atomic force microscopy) between the PCL microspheres and SS was reduced from 301.4 ± 21.7 nN to 110.9 ± 30.5 nN and 121.8 ± 24.6 nN, (p < 0.05, n = 5) for 1% and 2% MgSt solutions, respectively, and to 148.1 ± 21.0 nN when coated with leucine. The presence of PVA on the PCL microspheres (detected by X-ray photoelectron spectroscopy) affected the detachment of SS due to strong adhesion between the two, presumably due to capillary forces acting between them. Precoating the microspheres with excipients increased the FPF significantly by reducing the drug-carrier adhesion.

Docetaxel-loaded-lipid-based-nanosuspensions (DTX-LNS): preparation, pharmacokinetics, tissue distribution and antitumor activity

The purpose of the study was to design lipid-based-nanosuspensions (LNS) for Docetaxel (DTX) without Tween 80 for clinical intravenous administration (i.v.). DTX-LNS were prepared by high pressure homogenization method, and then lyophilization was carried out to improve the stability. The physical-chemical properties in terms of particle size, size distribution, zeta potential and morphology were evaluated, respectively. The in vitro cytotoxic activity was assessed by MTT against SKOV-3 and malignant melanoma B16 cells. The in vivo pharmacokinetics, tissue distribution as well as antitumor efficacy were investigated in B16 melanoma-bearing Kunming mice. The particle size and zeta potential of DTX-LNS were (200.0 ± 3.42)nm and (-11.15 ± 0.99)mV, respectively. Compared with Duopafei, it was shown that DTX-LNS exhibited higher antitumor efficacy by reducing tumor volume (P<0.05) and increasing survival rate in B16 melanoma-bearing mice and strongly reduced the anticancer drug toxicity. The results of biodistribution studies clearly indicated the superiority of DTX-LNS to Duopafei in increasing the accumulation of DTX within tumor and the organs rich in macrophages (liver, lungs and spleen), while, the drug concentration in heart and kidney decreased. Together these results suggested that DTX-LNS could effectively inhibit tumor growth, reduce toxicity during the therapeutic procedure and hold the potential to be an appropriate choice for the clinical administration of DTX.

Curcumin delivery by methoxy polyethylene glycol-poly(caprolactone) nanoparticles inhibits the growth of C6 glioma cells

As a potential anticancer agent, curcumin (Cum) has been reported for its chemopreventive and chemotherapeutic activity in a series of cancers through influencing cell cycle arrest, differentiation, apoptosis, etc. Therefore, the potential activity against various cancers of Cum raises the possibility of its application as a novel model drug in nanoparticle-based delivery systems. The current study reported a spherical core-shell structure curcumin-loaded nanoparticle (Cum-np) formed by amphilic methoxy polyethylene glycol-poly(caprolactone) (mPEG-PCL) block copolymers. Characterization tests indicated that Cum was incorporated into mPEG-PCL-based nanoparticles with high encapsulation efficiency due to its lipophilicity. The incorporated Cum could be released from Cum-np in a sustained manner. Cum was effectively transported into the cells by nanoparticles through endocytosis and localized around the nuclei in the cytoplasms. In vitro studies proved that the cytotoxicity of Cum-np would be pro-apoptosis effect against rat C6 glioma cell line in a dose-dependent manner. The present results suggest that Cum-np could be a potential useful chemotherapeutic formulation for malignant glioma therapy. Moreover, the development of traditional Chinese medicine with nanoscale drug formation warrants more intensive research for its clinical applications.

Docetaxel-loaded pluronic p123 polymeric micelles: in vitro and in vivo evaluation

In this work, novel docetaxel (DTX) -loaded Tween 80-free Pluronic P123 (P123) micelles with improved therapeutic effect were developed. The freeze-dried DTX-loaded P123 micelles (DTX-micelles) were analyzed by HPLC, TEM and DLS to determine the DTX loading, micelle morphology, size, respectively. The in vitro cytotoxic activity of DTX-micelles in HepG2, A549 and malignant melanoma B16 cells were evaluated by MTT assay. The corresponding in vivo antitumor efficacy was assessed in Kunming mice bearing B16 tumor after intravenous administration. The DTX-loading and efficiency into the micelles were 2.12 ± 0.09% and 86.34 ± 3.32%, respectively. The DTX-micelles were spherical with a mean particle size of 50.7 nm and size distribution from 22 to 84 nm, which suggested that they should be able to selectively accumulate in solid tumors by means of EPR effect, with a zeta potential of -12.45 ± 3.24 mV. The in vitro release behavior of DTX from DTX-micelles followed the Weibull equation. Compared with Duopafei(®), DTX-micelles showed higher cytotoxicity against HepG2 (P < 0.01), A549 (P < 0.05) and B16 (P < 0.01) cells. In addition, DTX-micelles exhibited remarkable antitumor activity and reduced toxicity on B16 tumor in vivo. The tumor inhibition rates (TIR) of DTX-micelles was 91.6% versus 76.3% of Duopafei(®) (P < 0.01). These results suggested that P123 micelles might be considered as an effective DTX delivery system.

Nanostructured delivery system for zinc phthalocyanine: preparation, characterization, and phototoxicity study against human lung adenocarcinoma A549 cells

In this study, zinc phthalocyanine (ZnPc) was loaded onto poly-ɛ-caprolactone (PCL) nanoparticles (NPs) using a solvent emulsification–evaporation method. The process yield and encapsulation efficiency were 74.2% ± 1.2% and 67.1% ± 0.9%, respectively. The NPs had a mean diameter of 187.4 ± 2.1 nm, narrow distribution size with a polydispersity index of 0.096 ± 0.004, zeta potential of −4.85 ± 0.21 mV, and spherical shape. ZnPc has sustained release, following Higuchi’s kinetics. The photobiological activity of the ZnPc-loaded NPs was evaluated on human lung adenocarcinoma A549 cells. Cells were incubated with free ZnPc or ZnPc-loaded NPs for 4 h and then washed with phosphate-buffered saline. Culture medium was added to the wells containing the cells. Finally, the cells were exposed to red light (660 nm) with a light dose of 100 J/cm². The cellular viability was determined after 24 h of incubation. ZnPc-loaded NPs and free photosensitizer eliminated about 95.9% ± 1.8% and 28.7% ± 2.2% of A549 cells, respectively. The phototoxicity was time dependent up to 4 h and concentration dependent at 0–5 μg ZnPc. The cells viability decreased with the increase of the light dose in the range of 10–100 J/cm². Intense lysis was observed in the cells incubated with the ZnPcloaded NPs and irradiated with red light. ZnPc-loaded PCL NPs are the release systems that promise photodynamic therapy use.

Biodegradable polymeric nanoparticles based drug delivery systems

Biodegradable nanoparticles have been used frequently as drug delivery vehicles due to its grand bioavailability, better encapsulation, control release and less toxic properties. Various nanoparticulate systems, general synthesis and encapsulation process, control release and improvement of therapeutic value of nanoencapsulated drugs are covered in this review. We have highlighted the impact of nanoencapsulation of various disease related drugs on biodegradable nanoparticles such as PLGA, PLA, chitosan, gelatin, polycaprolactone and poly-alkyl-cyanoacrylates.