In Vivo Studies of Octreotide-Modified N-Octyl-O, N-Carboxymethyl Chitosan Micelles Loaded with Doxorubicin for Tumor-Targeted Delivery

Octreotide and Octreotide-derived delivery systems

Pharmaceutical peptide Octreotide is a somatostatin analog with targeting and therapeutic abilities. Over the last decades, Octreotide has been developed and approved to treat acromegaly and neuroendocrine tumours, and Octreotide-based radioactive conjugates have been leveraged clinically to detect small neuroendocrine tumour sites. Meanwhile, variety of Octreotide-derived delivery strategies have been proposed and explored for tumour targeted therapeutics or diagnostics in preclinical or clinical settings. In this review, we especially focus on the preclinical development and applications of Octreotide-derived drug delivery systems, diagnostic nanosystems, therapeutic nanosystems and multifunctional nanosystems, we also briefly discuss challenges and prospects of these Octreotide-derived delivery systems.

Calcium carbonate vaterite particles for drug delivery: Advances and challenges

The recent successful application of lipid-based nanoparticles as delivery vehicles in COVID-19 vaccines demonstrated the superior potential of nanoparticle-based technology for targeted drug delivery in biomedicine. Among novel, rapidly advancing delivery platforms, the inorganic nano/microparticles gradually reach new heights and attract well-deserved attention among scientists and clinicians. Calcium carbonate in its vaterite form is used as a biocompatible carrier for a progressively increasing number of biomedical applications. Its growing popularity is conferred by beneficial porosity of particles, high mechanical stability, biodegradability under certain physiological conditions, ability to provide a continuous steady release of bioactives, preferential safety profile, and low cost, which make calcium carbonate a suitable entity of highly efficacious formulations for controlled drug delivery and release. The focal point of the current review is the success of the recent vaterite applications in the delivery of various diagnostics and therapeutic drugs. The manuscript highlights the nuances of drug loading in vaterite particles, connecting it with particle morphology, size, and charge of the loaded molecules, payload concentration, mono- or multiple drug loading. The manuscript also depicts recent successful methods of increasing the loading capacity developed for vaterite carriers. In addition, the review describes the various administration routes for vaterite particles with bioactive payloads, which were reported in recent years. Special attention is given to the multi-drug-loaded vaterite particles ("molecular cocktails") and reports on their successful delivery in vitro and in vivo.

Chemical Modification of Chitosan for Developing Cancer Nanotheranostics

Cancer is a worldwide public health issue that has not been conquered. Theranostics, the combination of a therapeutic drug and imaging agent in one formulation using nanomaterials, has been developed to better cure cancer in recent years. Although diverse biomaterials have been applied in cancer theranostics, chitosan (CS), a natural polysaccharide bearing easy modification sites with excellent biocompatibility and biodegradability, shows great potential for developing cancer nanotheranostics. In this review, we seek to describe the chemical functionalities of CS used in cancer theranostics and their synthesis methods. We also present recent discoveries and research progresses on how the CS functionalization could improve the delivery efficiency of CS-based nanotheranostics. Finally, we report several case studies about the application of CS-based nanotheranostics. This paper focuses on the strategies to construct CS-based theranostics systems via chemical routes and highlights their applications in cancer treatment, which can provide useful references for further studies.

Electro-Acupuncture Promotes Accumulation of Paclitaxel by Altering Tumor Microvasculature and Microenvironment in Breast Cancer of Mice

Targeted drug delivery could increase the efficacy of chemotherapy, however, a plethora of obstacles exist in the current targeted delivery designs. In this study, we introduce a novel avenue of targeted drug delivery using electro-acupuncture and evaluate its effect on the distribution of paclitaxel in a breast cancer mouse model. Our results show that electro-acupuncture intervention significantly increased the intratumoral concentration of paclitaxel. The mice in acupuncture group showed shorter t_max, longer t_1/2 and higher AUC of paclitaxel as compared with that in paclitaxel-only group. Moreover, we found that the acupuncture intervention significantly induced cell apoptosis in tumors. The levels of COL IV and α-SMA increased in tumors of acupuncture group. The negative tumor metastasis biomarker, NM23, was significantly upregulated in tumors of mice in acupuncture group. Our results suggest that acupuncture intervention around the tumor area increases the local concentration of chemotherapeutic agents. The targeted effect of acupuncture is achieved by altering tumor microvasculature and microenvironment. Therefore, combined therapy of acupuncture with chemotherapeutic agents is promising in improving cancer treatment efficacy.

Efficacy of liposomal dosage forms and hyperosmolar salines in experimental pharmacotherapy of acute lung injury

Introduction: Hypertonic sodium chloride solutions and liposomal drugs with pulmotropic effect are of great interest for the treatment of acute lung injury (ALI). The results of the studies on the efficacy of hypertonic solutions and liposomes in ALI treatment are currently controversial.

Materials and methods: For the experiment, liposomes with dexamethasone, N-acetylcysteine (NAC), aprotinin and dye Cyanine-7 (Cy-7) were obtained. A liposome analysis was performed by means of spectrophotometry. ALI was modeled in rats by the administration of the damaging agents into the trachea. The experimental agents were injected once intravenously after the modeling of ALI. For experimental therapy used liposomal agents, 7.5% hypertonic saline (HS) and HyperHAES solutions in the respective groups. The efficacy of the therapy was assessed by the survival of animals, functional indicators of the cardiovascular and respiratory systems, and by the lung-body ratio. The biodistribution of liposomes after intravenous administration was investigated in mice through using a fluorescent dye Cy-7. The biodistribution of liposomes with Cy-7 was assessed using bioimaging according to the fluorescence intensity of internal organs (lungs, liver, and kidneys) and blood, expressed as dye concentration according to the calibration dependence of dye concentrarion on fluorescence intensity.

Results and discussion: All the studied liposomal drugs were effective for the pharmacological correction of ALI. Hypertonic solutions, unlike liposomal drugs, were less likely to prevent the development of pulmonary edema. All the studied therapeutic agents increased the survival rate of the laboratory animals with ALI. The most effective experimental agent was liposomal dexamethasone. The use of drugs in form of simple liposomes with average diameter of 350 nm provided for a higher concentration of the drug in the lungs within the first 40 minutes after intravenous administration.

Conclusion: Intravenous administration of liposomal forms is promising for the pharmacotherapy of acute lung injury.

Peptide-Based Drug-Delivery Systems in Biotechnological Applications: Recent Advances and Perspectives

Peptides of natural and synthetic sources are compounds operating in a wide range of biological interactions. They play a key role in biotechnological applications as both therapeutic and diagnostic tools. They are easily synthesized thanks to solid-phase peptide devices where the amino acid sequence can be exactly selected at molecular levels, by tuning the basic units. Recently, peptides achieved resounding success in drug delivery and in nanomedicine smart applications. These applications are the most significant challenge of recent decades: they can selectively deliver drugs to only pathological tissues whilst saving the other districts of the body. This specific feature allows a reduction in the drug side effects and increases the drug efficacy. In this context, peptide-based aggregates present many advantages, including biocompatibility, high drug loading capacities, chemical diversity, specific targeting, and stimuli responsive drug delivery. A dual behavior is observed: on the one hand they can fulfill a structural and bioactive role. In this review, we focus on the design and the characterization of drug delivery systems using peptide-based carriers; moreover, we will also highlight the peptide ability to self-assemble and to actively address nanosystems toward specific targets.

Aiming for the Insulin-like Growth Factor-1 system in breast cancer therapeutics

Despite the major discoveries occurred in oncology the recent years, breast malignancies remain one of the most common causes of cancer-related deaths for women in developed countries. Development of HER2-targeting drugs has been considered a breakthrough in anti-cancer approaches and alluded to the potential of targeting growth factors in breast cancer (BrCa) therapeutics. More than twenty-five years have passed since the Insulin-like Growth Factor-1 (IGF-1) system was initially recognized as a potential target candidate in BrCa therapy. To date, a growing body of studies have implicated the IGF-1 signaling with the BrCa biology. Despite the promising experimental evidence, the impression from clinical trials is rather disappointing. Several reasons may account for this and the last word regarding the efficacy of this system as a target candidate in BrCa therapeutics is probably not written yet. Herein, we provide the theoretical basis, as well as, a comprehensive overview of the current literature, regarding the different strategies targeting the various components of the IGF-1/IGF-1R axis in several pathophysiological aspects of BrCa, including the tumor micro-environment and cancer stemness. In addition, we review the rationale for targeting the IGF-1 system in the different BrCa molecular subtypes and in treatment resistant breast tumors with a focus on both the molecular mechanisms and on the clinical perspectives of such approaches in specific population subgroups. We also discuss the future challenges, as well as, the development of novel molecules and strategies targeting the system and suggest potential improvements in the field.

Enhanced antitumor activity of doxorubicin in breast cancer through the use of poly(butylcyanoacrylate) nanoparticles

The use of doxorubicin (DOX), one of the most effective antitumor molecules in the treatment of metastatic breast cancer, is limited by its low tumor selectivity and its severe side effects. Colloidal carriers based on biodegradable poly(butylcyanoacrylate) nanoparticles (PBCA NPs) may enhance DOX antitumor activity against breast cancer cells, thus allowing a reduction of the effective dose required for antitumor activity and consequently the level of associated toxicity. DOX loading onto PBCA NPs was investigated in this work via both drug entrapment and surface adsorption. Cytotoxicity assays with DOX-loaded NPs were performed in vitro using breast tumor cell lines (MCF-7 human and E0771 mouse cancer cells), and in vivo evaluating antitumor activity in immunocompetent C57BL/6 mice. The entrapment method yielded greater drug loading values and a controlled drug release profile. Neither in vitro nor in vivo cytotoxicity was observed for blank NPs. The 50% inhibitory concentration (IC50) of DOX-loaded PBCA NPs was significantly lower for MCF-7 and E0771 cancer cells (4 and 15 times, respectively) compared with free DOX. Furthermore, DOX-loaded PBCA NPs produced a tumor growth inhibition that was 40% greater than that observed with free DOX, thus reducing DOX toxicity during treatment. These results suggest that DOX-loaded PBCA NPs have great potential for improving the efficacy of DOX therapy against advanced breast cancers.

Development of poly (I:C) modified doxorubicin loaded magnetic dendrimer nanoparticles for targeted combination therapy

The objective of this study was to develop and evaluate the anticancer activity and the safety of a combinational drug delivery system using polyamidoamine (PAMAM) dendrimer-coated iron oxide nanoparticles for doxorubicin and poly I:C delivery in vitro. Dendrimer-coated magnetic nanoparticles (DcMNPs) are suitable for drug delivery system as nanocarriers with their following properties, such as surface functional groups, symmetry perfection, internal cavities, nano-size and magnetization. These nanoparticles could be targeted to the tumor site under a magnetic field since they have a magnetic core. DcMNPs were found as a convenient vehicle for targeted doxorubicin delivery in cancer therapy. Poly (I:C) binding on doxorubicin loaded DcMNPs (DcMNPs-Dox) was reported for the first time in the literature. It was also demonstrated that loading of doxorubicin into the cavities of DcMNPs increases the binding efficiency of poly (I:C) to the surface functional groups of dendrimer up to 10 times. When we compare the in vitro cytotoxic properties of doxorubicin, poly (I:C) and poly (I:C) bound doxorubicin loaded DcMNPs (PIC-DcMNPs-Dox), it was observed that PIC-DcMNPs-Dox show the highest cytotoxic effect by passing the cell resistance mechanisms on doxorubicin resistant MCF7 (MCF7/Dox) cells. Results demonstrated that applying PIC-DcMNPs-Dox would improve the efficacy by increasing the biocompatibility of system in blood stream and the toxicity inside tumor cells. These results provide invaluable information and new insight for the design and optimization of a novel combinational drug delivery system for targeted cancer therapy.

Receptor binding peptides for target-selective delivery of nanoparticles encapsulated drugs

Active targeting by means of drug encapsulated nanoparticles decorated with targeting bioactive moieties represents the next frontier in drug delivery; it reduces drug side effects and increases the therapeutic index. Peptides, based on their chemical and biological properties, could have a prevalent role to direct drug encapsulated nanoparticles, such as liposomes, micelles, or hard nanoparticles, toward the tumor tissues. A considerable number of molecular targets for peptides are either exclusively expressed or overexpressed on both cancer vasculature and cancer cells. They can be classified into three wide categories: integrins; growth factor receptors (GFRs); and G-protein coupled receptors (GPCRs). Therapeutic agents based on nanovectors decorated with peptides targeting membrane receptors belonging to the GPCR family overexpressed by cancer cells are reviewed in this article. The most studied targeting membrane receptors are considered: somatostatin receptors; cholecystokinin receptors; receptors associated with the Bombesin like peptides family; luteinizing hormone-releasing hormone receptors; and neurotensin receptors. Nanovectors of different sizes and shapes (micelles, liposomes, or hard nanoparticles) loaded with doxorubicin or other cytotoxic drugs and externally functionalized with natural or synthetic peptides are able to target the overexpressed receptors and are described based on their formulation and in vitro and in vivo behaviors.