Prominin-1-Specific Binding Peptide-Modified Apoferritin Nanoparticle Carrying Irinotecan as a Novel Radiosensitizer for Colorectal Cancer Stem-Like Cells

The Potential Role of Nanoparticles as an Anticancer Therapy in the Treatment of Rectal Cancer

Nanotechnology is a rapidly developing science and is applied in a variety of diagnostic and treatment technologies. Colorectal cancer is one of the deadliest human diseases, and hence, wide research is underway regarding its preventative measures. This review demonstrated that “nano” drug delivery systems have successfully transferred pharmaceutical drug particles at the nanoscale as compared to larger particles. Research has shown a higher rate of disease progression among patients who receive conventional drugs compared to those who were given nanoscale drugs. However, the behavior of the cellular components differs from the performance of larger cellular components of the same type; these differences are due to the physical interactions between the nanoparticles (NPs). The review aimed to discuss several recent research studies focused on delivering NPs for the treatment of colorectal cancer (CRC). The reviewed experiments have primarily compared the use of NPs alone or with the addition of an anticancer drug or nanocarriers. These three research methods may help solve past problems and propose new future approaches for colorectal cancer by utilizing the available nanotechnologies. Furthermore, the review illustrated the underlying idea behind NP carriers and stem cell delivery that can be used to create a rapid delivery system for stem cells.

Preclinical evaluation of PEGylated liposomal doxorubicin as an effective radiosensitizer in chemoradiotherapy for lung cancer

PURPOSE

Development of a safe and effective systemic chemotherapeutic agent for concurrent administration with definitive thoracic radiotherapy remains a major goal of lung cancer management. The synergistic effect of PEGylated liposomal doxorubicin and irradiation was evaluated in lung cancer cell lines both in vitro and in vivo.

METHODS

In vitro radiosensitization of A549 and LLC cell lines was evaluated by colony formation assay, γH2AX fluorescent staining and western blot assay, and annexin V staining. A radiosensitization study with healthy human lung-derived cell line BEAS-2B was performed for comparative purposes. In vivo radiosensitization was evaluated by tumor ectopic growth, cell survival, pharmacokinetics, and biodistribution analyses. Cleaved caspase‑3, the marker for apoptosis, was assessed immunohistochemically in A549 xenograft tumors.

RESULTS

Treatment with PEGylated liposomal doxorubicin decreased A549 and LLC cell proliferation in a dose-dependent manner. In vitro studies revealed comparable radiosensitizer advantages of PEGylated liposomal doxorubicin and free doxorubicin, showing equivalent DNA double-strand breaks according to γH2AX fluorescent staining and western blot assays, similar numbers of apoptotic cells in the annexin‑V staining assay, and moderately decreased clonogenic survival. In vivo studies demonstrated markedly slow ectopic tumor growth with prolonged survival following treatment with PEGylated liposomal doxorubicin plus irradiation in both A549 and LLC mouse models, suggesting that PEGylated liposomal doxorubicin is more effective as a radiosensitizer than free doxorubicin in vivo. Pharmacokinetics evaluation showed a longer half-life of approximately 40 h for PEGylated liposomal doxorubicin, confirming that the liposomal carrier achieved controlled release. Biodistribution evaluation of PEGylated liposomal doxorubicin confirmed high accumulation of doxorubicin in tumors, indicating the promising drug delivery attributes of PEGylated liposomal doxorubicin. Although free doxorubicin caused histopathologic myocarditis with the cardiac muscle fibers showing varying degrees of damage, PEGylated liposomal doxorubicin caused no such effects. The immunohistochemical expression of cleaved caspase-3-positive cells was greatest expressed in the irradiation and PEGylated liposomal doxorubicin combined treatment group, indicating prolonged tumoricidal effects.

CONCLUSIONS

Our study provides preclinical in vitro and in vivo evidence of the effectiveness of PEGylated liposomal doxorubicin as a radiosensitizer, supporting its potential clinical development as a component of chemoradiotherapy.

Evaluation of antitumor immunity by a combination treatment of high-dose irradiation, anti-PDL1, and anti-angiogenic therapy in murine lung tumors

C57BL/6 mice implanted in the flank with murine Lewis lung carcinoma cells were randomized into control, anti-angiogenic, anti-PD-L1, radiotherapy (RT), RT + anti-angiogenic, RT + anti-PD-L1, and RT + anti-PD-L1 + anti-angiogenic therapy groups. Immune response and immunophenotyping were determined by flow cytometry. Vasculature analysis after RT and anti-angiogenic therapy was assessed by quantified power Doppler sonography. Antitumor response, survival, and rechallenged tumor growth were evaluated. RT increased PD-L1 expression on CD8+ T, CD4+ T, dendritic, myeloid-derived suppressor cells (MDSCs), and tumor cells and increased PD-1 expression on CD8+ and CD4+ T cells. Anti-angiogenic therapy insignificantly decreased the RT-induced PD-1 expression on CD8+ and CD4+ T cells, implying a weak reversal of the immune-suppressive environment. Transient vessel collapse was observed within days after RT, and blood flow recovered at 1 week after RT. RT + anti-PD-L1 suppressed the tumor growth, improved survival, and prolonged immune memory capable of protecting against tumor recurrence, evidenced by local accumulation of CD8+ T cells and reduction in MDSCs in microenvironment. Similar and more prominent effects were observed when anti-VEGF was added to RT + anti-PDL1 therapies, implying an additive, rather than synergistic, antitumor immunity. Phenotypic analyses revealed that anti-cancer treatments increased the proportion of effector memory T cells in TILs and splenocytes, and RT, alone or in combination with other treatments, further increased the proportion of central memory T cells in splenocytes. These results provide evidence on operating the immunosuppressive tumor environment and offer insights into the design of the new combination treatment.

Topoisomerase inhibitors: Pharmacology and emerging nanoscale delivery systems

Topoisomerase enzymes have shown unique roles in replication and transcription. These enzymes which were initially found in Escherichia coli have attracted considerable attention as target molecules for cancer therapy. Nowadays, there are several topoisomerase inhibitors in the market to treat or at least control the progression of cancer. However, significant toxicity, low solubility and poor pharmacokinetic properties have limited their wide application and these characteristics need to be improved. Nano-delivery systems have provided an opportunity to modify the intrinsic properties of molecules and also to transfer the toxic agent to the target tissues. These delivery systems leads to the re-introduction of existing molecules present in the market as novel therapeutic agents with different physicochemical and pharmacokinetic properties. This review focusses on a variety of nano-delivery vehicles used for the improvement of pharmacological properties of topoisomerase inhibitors and thus enabling their potential application as novel drugs in the market.

Near-Infrared Fluorescent Dye-Decorated Nanocages to Form Grenade-like Nanoparticles with Dual Control Release for Photothermal Theranostics and Chemotherapy

Recently, nanoparticles (NPs) have been widely investigated for delivery of anticancer drugs. Here, a dual control drug-release modality was developed that uses naturally occurring protein apoferritin loaded with doxorubicin (DOX) and ADS-780 near-infrared (NIR) fluorescent dye-decorated NPs (ADNIR NPs). ADNIR NPs act as a grenade to detonate the targeted tumor site following laser irradiation (photothermal therapy, PTT) and explode into cluster warheads (apoferritin-loaded DOX nanocages, AF-DOX NCs) that further destroy the tumor cells (chemotherapy). Light was shown to disrupt the grenade-like structure of NPs to release AF-DOX NCs as well as DOX from NCs in low-pH intercellular environments. In vitro and in vivo studies showed that the structure of AF-DOX NCs was disassembled to release DOX, which then killed the cancer cells in organelles with acidic environments. In vivo studies showed that the ADNIR NP-decorated with NIR dye facilitated tracking of the accumulated NPs at the tumor site using an IVIS imaging system. Overall, targeted ADNIR NPs with dual-release mechanisms were developed for use in photothermal theranostic and chemotherapy. This modality has high potential for application in cancer treatment and clinical translation for drug delivery and imaging.

Panitumumab-Conjugated and Platinum-Cored pH-Sensitive Apoferritin Nanocages for Colorectal Cancer-Targeted Therapy

Apoferritin (AF) is a natural nontoxic iron carrier and has a natural hollow structure that can be used to deliver small molecules. The surface of AF has many amine functional groups that can be modified to create targeted ligands. We loaded oxaliplatin onto AF, which was then used as a template to conjugate with panitumumab via a polyethylene glycol linker. The oxaliplatin-loaded AF conjugated with panitumumab (AFPO) was designed to specifically target cell lines expressing epidermal growth factor receptor (EGFR). AFPO efficiently released oxaliplatin and suppressed tumor cell growth. Furthermore, the novel AFPO nanocages showed significant inhibition and greater accumulation in tumor models with high EGFR expression in vivo. Our study revealed that combining panitumumab and oxaliplatin into one formulation (AFPO nanocage) could be a promising shortcut in clinical applications.

Nano-delivery system targeting to cancer stem cell cluster of differentiation biomarkers

Cancer stem cells (CSCs) are one of the most important origins of cancer progression and metastasis. CSCs have unique self-renewal properties and diverse cell membrane receptors that induced the resistance to the conventional chemotherapeutic agents. Therefore, the therapeutic removal of CSCs could result in the cancer cure with lack of recurrence and metastasis. In this regard, targeting CSCs in accordance to their specific biomarkers is a talented attitude in cancer therapy. Various CSCs surface biomarkers have been described, which some of them exhibited similarities on different cancer cell types, while the others are cancer specific and have just been reported on one or a few types of cancers. In this review, the importance of CSCs in cancer development and therapeutic response has been stated. Different CSCs cluster of differentiation (CD) biomarkers and their specific function and applications in the treatment of cancers have been discussed, Special attention has been made on targeted nano-delivery systems. In this regard, several examples have been illustrated concerning specific natural and artificial ligands against CSCs CD biomarkers that could be decorated on various nanoparticulated drug delivery systems to enhance therapeutic index of chemotherapeutic agents or anticancer gene therapy. The outlook of CSCs biomarkers discovery and therapeutic/diagnostic applications was discussed.