An increasing number of studies published so far have evidenced the benefits of Simvastatin (SIM) and Doxorubicin (DOX) co-treatment in colorectal cancer. In view of this, the current study aimed to investigate the pharmaceutical development of liposomes co-encapsulating SIM and DOX, by implementing the Quality by Design (QbD) concept, as a means to enhance the antiproliferative effect of the co-formulation on C26 murine colon cancer cells co-cultured with macrophages. It is known that the quality profile of liposomes is dependent on the critical quality attributes (CQAs) of liposomes (drug entrapped concentration, encapsulation efficiency, size, zeta potential, and drug release profile), which are, in turn, directly influenced by various formulation factors and processing parameters. By using the design of experiments, it was possible to outline the increased variability of CQAs in relation to formulation factors and identify by means of statistical analysis the material attributes that are critical (phospholipids, DOX and SIM concentration) for the quality of the co-formulation. The in vitro studies performed on a murine colon cancer cell line highlighted the importance of delivering the optimal drug ratio at the target site, since the balance antiproliferative vs. pro-proliferative effects can easily be shifted when the molar ratio between DOX and SIM changes.

Regardless of recent progress, melanoma is very difficult to treat, mainly due to the drug resistance modulated by tumor cells as well as by the tumor microenvironment (TME). Among the immune cells recruited at the tumor site, tumor associated macrophages (TAMs) are the most abundant, promoting important tumorigenic processes: angiogenesis, inflammation and invasiveness. Furthermore, it has been shown that TAMs are involved in mediating the drug resistance of melanoma cells. Thus, in the present study, we used liposomal formulation of prednisolone disodium phosphate (LCL-PLP) to inhibit the protumor function of TAMs with the aim to sensitize the melanoma cells to the cytotoxic drug doxorubicin (DOX) to which human melanoma has intrinsic resistance. Consequently, we evaluated the in vivo effects of the concomitant administration of LCL-PLP and liposomal formulation of DOX (LCL-DOX) on B16.F10 melanoma growth and on the production of key molecular markers for tumor development. Our results demonstrated that the concomitant administration of LCL-PLP and LCL-DOX induced a strong inhibition of tumor growth, primarily by inhibiting TAMs-mediated angiogenesis as well as the tumor production of MMP-2 and AP-1. Moreover, our data suggested that the combined therapy also affected TME as the number of infiltrated macrophages in melanoma microenvironment was reduced significantly.

Curcumin’s role in the treatment of ulcerative colitis (UC) has been proven by numerous studies, but its preventive administration, with the aim of reducing the remission episodes that are characteristic of this disease, must be further investigated. This study investigates the effects of a novel curcumin-loaded polymeric microparticulate oral-drug-delivery system for colon targeting (Col-CUR-MPs) in an experimental model of UC. Male Wistar rats (n = 40) were divided into five groups (n = 8), which were treated daily by oral gavage for seven days with a 2% aqueous solution of carboxymethylcellulose sodium salt (CMCNa) (healthy and disease control), free curcumin powder (reference), Col-CUR-MPs (test) and prednisolone (reference) prior to UC induction by the intrarectal administration of acetic acid (AA), followed by animal sacrification and blood and colonic samples’ collection on the eighth day. Col-CUR-MPs exhibited an important preventive effect in the severity degree of oxidative stress that resulted following AA intrarectal administration, which was proved by the highest catalase (CAT) and total antioxidant capacity (TAC) levels and the lowest nitrites/nitrates (NOx), total oxidative status (TOS) and oxidative stress index (OSI) levels. Biochemical parameter analysis was supported by histopathological assessment, confirming the significant anti-inflammatory and antioxidant effects of this novel colon-specific delivery system in AA-induced rat models of UC. Thus, this study offers encouraging perspectives regarding the preventive administration of curcumin in the form of a drug delivery system for colon targeting.

Anti-angiogenic therapies for melanoma have not yet been translated into meaningful clinical benefit for patients, due to the development of drug-induced resistance in cancer cells, mainly caused by hypoxia-inducible factor 1α (HIF-1α) overexpression and enhanced oxidative stress mediated by tumor-associated macrophages (TAMs). Our previous study demonstrated synergistic antitumor actions of simvastatin (SIM) and 5,6-dimethylxanthenone-4-acetic acid (DMXAA) on an in vitro melanoma model via suppression of the aggressive phenotype of melanoma cells and inhibition of TAMs-mediated angiogenesis. Therefore, we took the advantage of long circulating liposomes (LCL) superior tumor targeting capacity to efficiently deliver SIM and DMXAA to B16.F10 melanoma in vivo, with the final aim of improving the outcome of the anti-angiogenic therapy. Thus, we assessed the effects of this novel combined tumor-targeted treatment on s.c. B16.F10 murine melanoma growth and on the production of critical markers involved in tumor development and progression. Our results showed that the combined liposomal therapy almost totally inhibited (> 90%) the growth of melanoma tumors, due to the enhancement of anti-angiogenic effects of LCL-DMXAA by LCL-SIM and simultaneous induction of a pro-apoptotic state of tumor cells in the tumor microenvironment (TME). These effects were accompanied by the partial re-education of TAMs towards an M1 phenotype and augmented by combined therapy-induced suppression of major invasion and metastasis promoters (HIF-1α, pAP-1 c-Jun, and MMPs). Thus, this novel therapy holds the potential to remodel the TME, by suppressing its most important malignant biological capabilities.

Colorectal cancer remains one of the major causes of morbidity and mortality in both developed and emerging countries. Cancer stem cells (CSCs) are a subpopulation of cells within the tumor mass harboring stem cell characteristics, considered responsible for tumor initiation, growth, relapse, and treatment failure. Lately, it has become clear that both CSCs and non-CSCs have to be eliminated for the successful eradication of cancer. Drug delivery systems have been extensively employed to enhance drug efficacy. In this study, salinomycin (SAL), a selective anti-CSC drug, and gemcitabine (GEM), a conventional anticancer drug, were co-loaded in liposomes and tested for optimal therapeutic efficacy. We employed the Design of Experiments approach to develop and optimize a liposomal delivery system for GEM and SAL. The antiproliferative effect of the liposomes was evaluated in SW-620 human colorectal cancer cells. The GEM and SAL-loaded liposomes exhibited adequate size, polydispersity, zeta potential, and drug content. The in vitro release study showed a sustained release of GEM and SAL from the liposomes over 72 h. Moreover, no sign of liposome aggregation was seen over 1 month and in a biological medium (FBS). The in vitro cytotoxic effects of the co-loaded liposomes were superior to that of single GEM either in free or liposomal form. The combination therapy using GEM and SAL co-loaded in liposomes could be a promising strategy for tackling colorectal cancer.