Liposomal delivery and polyethylene glycol-liposomal oxaliplatin for the treatment of colorectal cancer (Review)

Nanoparticles Containing Oxaliplatin and the Treatment of Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) is a highly widespread malignancy and ranks as the second most common cause of cancer-related mortality.

OBJECTIVE

Cancer patients, including those with CRC, who undergo chemotherapy, are often treated with platinum- based anticancer drugs such as oxaliplatin (OXA). Nevertheless, the administration of OXA is associated with a range of gastrointestinal problems, neuropathy, and respiratory tract infections. Hence, it is necessary to devise a potential strategy that can effectively tackle these aforementioned challenges. The use of nanocarriers has shown great potential in cancer treatment due to their ability to minimize side effects, target drugs directly to cancer cells, and improve drug efficacy. Furthermore, numerous studies have been published regarding the therapeutic efficacy of nanoparticles in the management of colorectal cancer.

METHODS

In this review, we present the most relevant nanostructures used for OXA encapsulation in recent years, such as solid lipid nanoparticles, liposomes, polysaccharides, proteins, silica nanoparticles, metal nanoparticles, and synthetic polymer-carriers. Additionally, the paper provides a summary of the disadvantages and limits associated with nanoparticles.

RESULTS

The use of different carriers for the delivery of oxaliplatin increased the efficiency and reduced the side effects of the drug. It has been observed that the majority of research investigations have focused on liposomes and polysaccharides.

CONCLUSION

This potentially auspicious method has the potential to enhance results and enhance the quality of life for cancer patients undergoing chemotherapy. However, additional investigation is required to ascertain the most suitable medium for the transportation of oxaliplatin and to assess its efficacy through clinical trials.

In-vitro evaluation of dendrimeric formulation of oxaliplatin

The aim of this study is, preparing various dendrimeric formulations of oxaliplatin and investigating their properties. First of all, the solubility enhancement capabilities of polyamidoamine (PAMAM) G3.5 and PAMAM G4.5 dendrimers were investigated. The results showed that oxaliplatin solubility mostly increasing linearly with dendrimer concentration. Additionally, the increase was more notable in PAMAM G4.5 dendrimers. Then, drug-dendrimer complexes were prepared in different mediums, since the medium used can affect the amount of drug-loaded to dendrimers. Prepared complexes were examined for loading capacity and loading efficiency. It was found that PAMAM G4.5 dendrimers can complex with 2- to 5-fold more oxaliplatin than PAMAM G3.5. Finally, oxaliplatin was modified to a platinum (IV) compound to prepare chemical drug-dendrimer conjugates. Ester bonds were established by Steglich esterification through the hydroxyl group of modified oxaliplatin and the carboxyl groups of the dendrimers. The formulations were characterized by UV, IR, NMR spectroscopy, and dynamic light scattering techniques. PAMAM G3.5 conjugate was further evaluated for the cytotoxicity test. The IC₅₀ value of PAMAM G3.5 conjugate was found as 0.72 µM. For unmodified oxaliplatin, this value was 14.03 µM. As a result, a dendrimer-based drug delivery system that has been found promising for further improvement has been developed successfully.

Characterization and Pharmacokinetic Evaluation of Oxaliplatin Long-Circulating Liposomes

The clinical efficacy of Oxaliplatin (L-OHP) is potentially limited by dose-dependent neurotoxicity and high partitioning to erythrocytes in vivo. Long-circulating liposomes could improve the pharmacokinetic profile of L-OHP and thus enhance its therapeutic efficacy and reduce its toxicity. The purpose of this study was to prepare L-OHP long-circulating liposomes (L-OHP PEG lip) by reverse-phase evaporation method (REV) and investigate their pharmacokinetic behavior based on total platinum in rat plasma using atomic absorption spectrometry (AAS). A simple and a sensitive AAS method was developed and validated to determine the total platinum originated from L-OHP liposomes in plasma. Furthermore, long-circulating liposomes were fully characterized in vitro and showed great stability when stored at 4°C for one month. The results showed that the total platinum in plasma of L-OHP long-circulating liposomes displayed a biexponential pharmacokinetic profile with five folds higher bioavailability and longer distribution half-life compared to L-OHP solution. Thus, long-circulating liposomes prolonged L-OHP circulation time and may present a potential candidate for its tumor delivery. Conclusively, the developed AAS method could serve as a reference to investigate the pharmacokinetic behavior of total platinum in biological matrices for other L-OHP delivery systems.

An Update on the Pharmacological Usage of Curcumin: Has it Failed in the Drug Discovery Pipeline?

The pharmacological propensities of curcumin have been reported in a plethora of pre-clinical and clinical studies. However, innate attributes account for extremely low oral bioavailability which impedes its development as a therapeutic agent. Regardless, these drawbacks have not deterred researchers from optimizing its potentials. This review discussed the pharmacokinetic properties of curcumin relative to its outlook as a lead compound in drug discovery. Also, we highlighted therapeutic strategies that have expedited improvements in curcumin oral bioavailability and delivery to target sites over the years. Recent implementations of these strategies were also covered. More research efforts should be directed towards investigating the pharmacokinetic impacts of these novel curcumin formulations in human clinical studies since inter-species disparities could limit the accuracies of animal studies. We envisaged that integrative-clinical research would help determine 'actual' improvements in curcumin pharmacokinetics coupled with suitable administrative routes, optimal dosing, and drug-enzyme or drug-drug interactions. In addition, this could help determine formulations for achieving higher systemic exposure of parent curcumin thereby providing a strong impetus towards the development of curcumin as a drug candidate in disease treatment.

Multifunctional nanomedicines for targeting epidermal growth factor receptor in colorectal cancer

Systemic administration of chemotherapeutics by nanocarriers (NCs) functionalized with targeting agents provides a localized accumulation of drugs in the target tissues and cells. Advanced nanoscaled medicaments can enter into the tumor microenvironment (TME) and overcome the uniquely dysregulated biological settings of TME, including highly pressurized tumor interstitial fluid in an acidic milieu. Such multimodal nanomedicines seem to be one of the most effective treatment modalities against solid tumors such as colorectal cancer (CRC). To progress and invade, cancer cells overexpress various oncogenes and molecular markers such as epidermal growth factor receptors (EGFRs), which can be exploited for targeted delivery of nanoscaled drug delivery systems (DDSs). In fact, to develop effective personalized multimodal nanomedicines, the type of solid tumor and status of the disease in each patient should be taken into consideration. While the development of such multimodal-targeted nanomedicines is largely dependent on the expression level of oncomarkers, the type of NCs and homing/imaging agents play key roles in terms of their efficient applications. In this review, we provide deep insights into the development of EGFR-targeting nanomedicines and discuss various types of nanoscale DDSs (e.g., organic and inorganic nanoparticles) for targeting of the EGFR-positive solid tumors such as CRC.

Prdx2 Upregulation Promotes the Growth and Survival of Gastric Cancer Cells

Peroxiredoxins (Prdxs) play important roles in cell proliferation, differentiation, and the mediation of intracellular signalling pathways. Prdx2 is an important member of the peroxiredoxin family and is upregulated in many cancers. Until now, the biological functions of Prdx2 in gastric cancer have not been completely understood, and the underlying mechanisms remain elusive. The aim of this study was to identify the role of Prdx2 on the growth of gastric cancer cells and the underlying mechanisms. We demonstrated that Prdx2 was highly expressed in gastric cancer tissues and cell lines and that the over-expression of Prdx2 correlated with the progression of gastric cancer. Further, Prdx2 was silenced with a specific, lentiviral vector-mediated shRNA, and this suppressed the proliferation of gastric cancer cells and promoted the apoptosis of gastric cancer cells. Finally, the knockdown of Prdx2 contributed to the attenuated gastric cancer growth in BALB/c nude mice. In conclusion, these findings demonstrate that Prdx2 may participate in the carcinogenesis and development of gastric cancer.

Preparation and Evaluation of Oxaliplatin Thermosensitive Liposomes with Rapid Release and High Stability

Oxaliplatin (OXP) was reported to show low anti-tumor activity when used alone and to display side effects; this low activity was attributed to high partitioning to erythrocytes and low accumulation in tumors. Thermosensitive liposomes (TSL) were considered able to specifically deliver drugs to heated tumors and to resolve the OXP distribution problem. Regretfully, TSL encapsulating doxorubicin did not demonstrate significant improvement in progression-free survival. Drug release below 41°C and significant leakage were considered major reasons for the failure. The purpose of this study was to acquire OXP TSL with rapid release at the triggered temperature and high stability at body temperature and at storage temperatures. A small quantity of poloxamer 188 was introduced into the TSL formulation to stabilize the encapsulated drug. It was shown that the addition of poloxamer 188 had no influence on the TSL characteristics. More than 90% of OXP was released within 10 min at 42°C, and less than 15% was released within 60 min at temperatures below 39°C. TSL were stable at 37°C for 96 h and at 4°C for 6 months. The anti-tumor activity of TSL at the dose of 2.5 mg/kg was certified to be equal to those of OXP injection and non-thermosensitive liposomes (NTSL) at the dose of 5 mg/kg, and significant improvement of tumor inhibition was observed in TSL compared with injection and NTSL at the same dose. It was also shown from the histological transmutation of tumors that TSL had stronger anti-tumor activity. Therefore, it could be concluded that TSL composed of a proper amount of poloxamer had rapid release and high stability, and OXP TSL would be anticipated to exert prominent anti-tumor activity in the clinic.

Combination of gemcitabine-containing magnetoliposome and oxaliplatin-containing magnetoliposome in breast cancer treatment: A possible mechanism with potential for clinical application

Breast cancer is a major global health problem with high incidence and case fatality rates. The use of magnetoliposomes has been suggested as an effective therapeutic approach because of their good specificity for cancers. In this study, we developed two novel magnetoliposomes, namely, Gemcitabine-containing magnetoliposome (GML) and Oxaliplatin-containing magnetoliposome (OML). These magnetoliposomes were combined (CGOML) was used to treat breast cancer under an external magnetic field. Biosafety test results showed that GML and OML were biologically safe to blood cells and did not adversely affect the behavior of mice. Pharmacokinetic and tissue distribution studies indicated that both magnetoliposomes exhibited stable structures and persisted at the target area under an external magnetic field. Cell and animal experiments revealed that CGOML can markedly suppress the growth of MCF-7 cells, and only the CGOML group can minimize the tumor size among all the groups. Finally, CGOML can significantly inhibit MCF-7cell growth both in vitro and vivo by activating the apoptotic signaling pathway of MCF-7 cells.

Development of tumor-specific caffeine-potentiated chemotherapy using a novel drug delivery system with Span 80 nano-vesicles

In recent years, chemotherapy with caffeine has manifested potently high efficacy against osteosarcoma, although adverse effects have been observed. Recently, we developed a novel drug delivery system (DDS) with nonionic vesicles prepared from Span 80 which have promising physicochemical properties as an attractive possible alternative to commonly used liposomes. Herein, we demonstrated that tumor-specific caffeine-potentiated chemotherapy for murine osteosarcoma administered by a novel DDS with Span 80 nano-vesicles showed significant antitumor effects as well as limited adverse effects. The osteosarcoma cell line, LM8, was transplanted into C3H/HeJ mice which then were administered therapeutic agents. Ifosfamide (IFO) was employed as well as caffeine as an enhancer. Span 80 vesicles containing IFO and/or caffeine were freshly prepared. On days 0, 2 and 4, different combinations of the agents were administered to mice: IFO alone (direct i.v.), IFO vesicles (IV), IV + caffeine, IV + caffeine vesicles (CV), PBS alone vesicles (PV), and PBS alone as negative control (PBS i.v.). Then, the mice were sacrificed on day 7. Antitumor effects of the reagents were also analyzed in vitro. Moreover, fertility examination was performed. In vitro, a combination of IV+CV showed significant induction of apoptosis in the early phase. Tumor volumes in the IV+CV group were significantly reduced compared with the other groups. Histological analyses showed that the IV and IV+CV groups had significantly lower viable tumor areas. The IFO direct i.v. group showed a certain grade of renal injury as well as marked suppression of spermatogenesis, while the IV or IV+CV group showed no marked changes. The fertility test revealed that the male mice with IV+CV administration had normal fertility, and no malformations were detected in their progeny. This DDS model is of potential importance for clinical application in the therapy of metastatic osteosarcoma.