Enhanced Cytotoxic Effect of Doxorubicin Conjugated to Glutathione-Stabilized Gold Nanoparticles in Canine Osteosarcoma-In Vitro Studies

Human and canine osteosarcoma cell lines: How do they react upon incubation with calcium phosphate-coated lipid nanoparticles carrying doxorubicin and curcumin?

Osteosarcoma (OSA) is a bone cancer that affects both humans and animals, with dogs being particularly vulnerable. Standard therapy is often limited by multidrug resistance (MDR), primarily due to the overexpression of P-glycoprotein (P-gp), which expels drugs from the cells, reducing their efficacy. To overcome this challenge, drug delivery systems (DDS) and P-gp modulators have been explored. However, developing DDS that selectively target cancer cells remains difficult, with many current options lacking efficiency. Our research group has recently developed an innovative type of nanoparticle with a lipid core and a calcium phosphate shell (CaP-NPs), which enhances the uptake of doxorubicin (DOXO) in OSA cells. In this study, we loaded a lipophilic ester of doxorubicin (C12DOXO) and curcumin (CURC), a natural P-gp modulator, into CaP-NPs and co-incubated them into human and canine OSA cell lines, including DOXO-resistant cells. The results demonstrated a significant reduction in viability in human OSA cells. Additionally, the combination treatment led to a further increase in C12DOXO retention when cells were also treated with the P-gp inhibitor verapamil, indicating enhanced efficacy against MDR mechanisms. Notably, canine OSA cells exhibited a distinct response pattern, suggesting the presence of species-specific differences that warrant further investigation.

Exosomes in Bone Cancer: Unveiling their Vital Role in Diagnosis, Prognosis, and Therapeutic Advancements

Bone cancer among adolescents and children exhibits varying survival outcomes based on disease state. While localized bone cancer cases have a survival rate exceeding 70%, metastatic, refractory, and recurrent forms are associated with significantly poorer prognoses. Initially believed to be mere vehicles for cellular waste disposal, exosomes are now recognized as extracellular vesicles facilitating intercellular communication. These vesicles influence cellular behaviors by transporting various biomolecules, such as proteins, DNA, RNA, and lipids, among cells. The role of exosomes in regulating the progression of bone cancer is increasingly evident, impacting critical processes like tumorigenesis, proliferation, metastasis, angiogenesis, immune evasion, and drug resistance. Current research underscores the substantial potential of exosomes in promoting the progression and development of bone cancer. This review delves into the complex process of exosome biogenesis, the variety of cell-derived exosome sources, and their applications in drug delivery and therapeutics. It also examines ongoing clinical trials focused on exosome cargo levels and discusses the challenges and future directions in exosome research. Unlike costly and invasive traditional diagnostic methods, exosomal biomarkers offer a non-invasive, cost-effective, and readily accessible routine screening through simple fluid collection that aims to inspire researchers to investigate the potential of exosomes for cancer theragnostic. Through comprehensive exploration of these areas, the review seeks to enhance understanding and foster innovative solutions to cancer biology in the near future.

Meeting Contemporary Challenges: Development of Nanomaterials for Veterinary Medicine

In recent decades, nanotechnology has been rapidly advancing in various fields of human activity, including veterinary medicine. The review presents up-to-date information on recent advancements in nanotechnology in the field and an overview of the types of nanoparticles used in veterinary medicine and animal husbandry, their characteristics, and their areas of application. Currently, a wide range of nanomaterials has been implemented into veterinary practice, including pharmaceuticals, diagnostic devices, feed additives, and vaccines. The application of nanoformulations gave rise to innovative strategies in the treatment of animal diseases. For example, antibiotics delivered on nanoplatforms demonstrated higher efficacy and lower toxicity and dosage requirements when compared to conventional pharmaceuticals, providing a possibility to solve antibiotic resistance issues. Nanoparticle-based drugs showed promising results in the treatment of animal parasitoses and neoplastic diseases. However, the latter area is currently more developed in human medicine. Owing to the size compatibility, nanomaterials have been applied as gene delivery vectors in veterinary gene therapy. Veterinary medicine is at the forefront of the development of innovative nanovaccines inducing both humoral and cellular immune responses. The paper provides a brief overview of current topics in nanomaterial safety, potential risks associated with the use of nanomaterials, and relevant regulatory aspects.

Gold Nanoparticles Inhibit Extravasation of Canine Osteosarcoma Cells in the Ex Ovo Chicken Embryo Chorioallantoic Membrane Model

Canine osteosarcoma (OS) is an aggressive bone tumor with high metastatic potential and poor prognosis, mainly due to metastatic disease. Nanomedicine-based agents can be used to improve both primary and metastatic tumor treatment. Recently, gold nanoparticles were shown to inhibit different stages of the metastatic cascade in various human cancers. Here, we assessed the potential inhibitory effect of the glutathione-stabilized gold nanoparticles (Au-GSH NPs) on canine OS cells extravasation, utilizing the ex ovo chick embryo chorioallantoic membrane (CAM) model. The calculation of cells extravasation rates was performed using wide-field fluorescent microscopy. Transmission electron microscopy and Microwave Plasma Atomic Emission Spectroscopy revealed Au-GSH NPs absorption by OS cells. We demonstrated that Au-GSH NPs are non-toxic and significantly inhibit canine OS cells extravasation rates, regardless of their aggressiveness phenotype. The results indicate that Au-GSH NPs can act as a possible anti metastatic agent for OS treatment. Furthermore, the implemented CAM model may be used as a valuable preclinical platform in veterinary medicine, such as testing anti-metastatic agents.

PEG-liposomal doxorubicin as a potential agent for canine metastatic osteosarcoma - in vitro and ex ovo studies

Introduction

Appendicular osteosarcoma (OSA) is a highly aggressive and metastatic primary bone tumour in dogs. Standard therapy is amputation and adjuvant chemotherapy (e.g. with doxorubicin). Liposomal drug delivery may augment therapeutic efficacy and reduce negative side effects. Polyethylene glycol (PEG)-liposomal doxorubicin treats human metastatic cancers effectively. The study aimed was to evaluate PEG-liposomal doxorubicin's inhibitory effect on canine metastatic proliferation and migration in vitro. It also aimed to appraise the drug's extravasation inhibition in vivo using the human medicine-proven chick embryo chorioallantoic membrane ex ovo model.

Material and Methods

The canine D-17 OSA cell line was cultured and inoculated with decreasing concentrations of PEG-liposomal doxorubicin and conventional doxorubicin in a 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) test of cell viability, proliferation and cytotoxicity. Flow cytometry with Annexin V and Draq 7 staining confirmed the MTT test results, indicating dead, early and late apoptotic, and live cells. The inhibitory effect of the two preparations on cancer cell migration was investigated with a wound-healing assay. Culture plates seeded with cells were prepared. The cell monolayer was scratched and images of cells migrating to the scratch were captured at 0 h, 12 h and 24 h. Also, embryos were removed from three-day-incubated fertilised chicken eggs. On the 12th day, labelled D-17 cells were injected into each embryo. Embryos in one group received 100 μL of phosphate-buffered saline as controls, those in another group 30 μg/mL of PEG-liposomal doxorubicin, and those in the last group 6 μg/mL of conventional doxorubicin. The effectiveness of the intravascular administration of the D-17 cells was confirmed under a microscope.

Results

PEG-liposomal doxorubicin inhibited the migration of canine OSA cells more effectively than conventional doxorubicin (P ≤ 0.05). The ex ovo model showed that both drugs had similar impacts on canine metastatic OSA.

Conclusion

The liposomal form of the drug may be considered a potentially effective compound in canine metastatic OSA; nevertheless, further in vivo studies are essential to confirm this hypothesis.

Advanced nanoscale drug delivery systems for bone cancer therapy

Bone tumors are relatively rare, which are complex cancers and mostly involve the long bones and pelvis. Bone cancer is mainly categorized into osteosarcoma (OS), chondrosarcoma, and Ewing sarcoma. Of these, OS is the most intimidating cancer of the bone tissue, which is mostly found in the log bones in young children and older adults. Conspicuously, the current chemotherapy modalities used for the treatment of OS often fail mainly due to (i) the non-specific detrimental effects on normal healthy cells/tissues, (ii) the possible emergence of drug resistance mechanisms by cancer cells, and (iii) difficulty in the efficient delivery of anticancer drugs to the target cells. To impose the maximal therapeutic impacts on cancerous cells, it is of paramount necessity to specifically deliver chemotherapeutic agents to the tumor site and target the diseased cells using advanced nanoscale multifunctional drug delivery systems (DDSs) developed using organic and inorganic nanosystems. In this review, we provide deep insights into the development of various DDSs applied in targeting and eradicating OS. We elaborate on different DDSs developed using biomaterials, including chitosan, collagen, poly(lactic acid), poly(lactic-co-glycolic acid), polycaprolactone, poly(ethylene glycol), polyvinyl alcohol, polyethyleneimine, quantum dots, polypeptide, lipid NPs, and exosomes. We also discuss DDSs established using inorganic nanoscale materials such as magnetic NPs, gold, zinc, titanium NPs, ceramic materials, silica, silver NPs, and platinum NPs. We further highlight anticancer drugs' role in bone cancer therapy and the biocompatibility of nanocarriers for OS treatment.

Nanobiotechnological approaches in osteosarcoma therapy: Versatile (nano)platforms for theranostic applications

Constructive achievements in the field of nanobiotechnology and their translation into clinical course have led to increasing attention towards evaluation of their use for treatment of diseases, especially cancer. Osteosarcoma (OS) is one of the primary bone malignancies that affects both males and females in childhood and adolescence. Like other types of cancers, genetic and epigenetic mutations account for OS progression and several conventional therapies including chemotherapy and surgery are employed. However, survival rate of OS patients remains low and new therapies in this field are limited. The purpose of the current review is to provide a summary of nanostructures used in OS treatment. Drug and gene delivery by nanoplatforms have resulted in an accumulation of therapeutic agents for tumor cell suppression. Furthermore, co-delivery of genes and drugs by nanostructures are utilized in OS suppression to boost immunotherapy. Since tumor cells have distinct features such as acidic pH, stimuli-responsive nanoparticles have been developed to appropriately target OS. Besides, nanoplatforms can be used for biosensing and providing phototherapy to suppress OS. Furthermore, surface modification of nanoparticles with ligands can increase their specificity and selectivity towards OS cells. Clinical translation of current findings suggests that nanoplatforms have been effective in retarding tumor growth and improving survival of OS patients.

Nanocarriers in Veterinary Medicine: A Challenge for Improving Osteosarcoma Conventional Treatments

In recent years, several nanocarrier-based drug delivery systems, such as polymeric nanoparticles, solid lipid nanoparticles, metallic nanoparticles, liposomes, and others, have been explored to target and treat a wide variety of diseases. Their employment has brought many benefits, not only to human medicine but also to veterinary medicine, albeit at a slower rate. Soon, the use of nanocarriers could revolutionize the animal health sector, and many veterinary therapies will be more effective as a result. The purpose of this review is to offer an overview of the main applications of nanocarriers in the veterinary field, from supplements for animal health and reproduction to nanovaccines and nanotherapies. Among the major pathologies that can affect animals, special attention is given to canine osteosarcoma (OSA): a comparison with human OSA is provided and the main treatment options are reviewed emphasizing the benefits that nanocarriers could bring in the treatment of this widespread disease.

Co-Treatment of Caco-2 Cells with Doxorubicin and Gold Nanoparticles Produced from Cyclopia intermedia Extracts or Mangiferin Enhances Drug Effects

Mangiferin (MGF) is a natural and valuable polyphenol found in significant levels in many plant species, including Cyclopia intermedia (C. intermedia). In a previous study, we synthesized gold nanoparticles (AuNPs) using MGF and a water extract of C. intermedia and reported that these AuNPs have very low cytotoxicity toward a human colon cancer (Caco-2) cell line. Although the study also showed that these biogenic AuNPs in combination with doxorubic (DOX) significantly augmented the cytotoxic effects of DOX in Caco-2 cells, the mechanism of the enhanced effect was not fully understood, and it was also not known if other cell lines would be sensitive to this co-treatment. In the present study, we examined the cytotoxicity of the co-treatment in Caski, HeLa, HT-29, KMST-6 and MDA-321 cell lines. Additionally, we investigated the mechanistic effects of this co-treatment in Caco-2 cells using several assays, including the adenosine triphosphate (ATP), the oxidative stress, the mitochondrial depolarization, the colony formation, the APOPercentage and the DNA fragmentation assays. We also assessed the intracellular uptake of the biogenic AuNPs. The study showed that the biogenic AuNPs were effectively taken up by the cancer cells, which, in turn, may have enhanced the sensitivity of Caco-2 cells to DOX. Moreover, the combination of the biogenic AuNPs and DOX caused a rapid depletion of ATP levels, increased mitochondrial depolarization, induced apoptosis, reduced the production of reactive oxygen species (ROS) and inhibited the long-term survival of Caco-2 cells. Although the study provided some insight into the mechanism of cytotoxicity induced by the co-treatment, further mechanistic and molecular studies are required to fully elucidate the enhanced anticancer effect of the co-treatment.

Application of Biocompatible Drug Delivery Nanosystems for the Treatment of Naturally Occurring Cancer in Dogs

Background: Cancer is a common disease in dogs, with a growing incidence related to the age of the animal. Nanotechnology is being employed in the veterinary field in the same manner as in human therapy. Aim: This review focuses on the application of biocompatible nanocarriers for the treatment of canine cancer, paying attention to the experimental studies performed on dogs with spontaneously occurring cancer. Methods: The most important experimental investigations based on the use of lipid and non-lipid nanosystems proposed for the treatment of canine cancer, such as liposomes and polymeric nanoparticles containing doxorubicin, paclitaxel and cisplatin, are described and their in vivo fate and antitumor features discussed. Conclusions: Dogs affected by spontaneous cancers are useful models for evaluating the efficacy of drug delivery systems containing antitumor compounds.

Doxorubicin-Loaded Lipid Nanoparticles Coated with Calcium Phosphate as a Potential Tool in Human and Canine Osteosarcoma Therapy

Osteosarcoma (OSA) is the most frequently diagnosed primary malignant bone tumor in humans and dogs. In both species, standard chemotherapy can be limited by multidrug resistance of neoplastic cells, which prevents intracellular accumulation of cytotoxic drugs, resulting in chemotherapy failure. In this study, a lipophilic ester of doxorubicin (C12DOXO) was loaded into nanoparticles (NPs) using the “cold microemulsion dilution” method. The resulting NPs were then coated with calcium phosphate (CaP) in two different ways to have calcium or phosphate ions externally exposed on the surface. These systems were characterized by determining mean diameter, zeta potential, and drug entrapment efficiency; afterward, they were tested on human and canine OSA cells to study the role that the coating might play in increasing both drug uptake into tumor cells and cytotoxicity. Mean diameter of the developed NPs was in the 200–300 nm range, zeta potential depended on the coating type, and C12DOXO entrapment efficiency was in the 60–75% range. Results of studies on human and canine OSA cells were very similar and showed an increase in drug uptake and cytotoxicity for CaP-coated NPs, especially when calcium ions were externally exposed. Therefore, applications in both human and veterinary medicine can be planned in the near future.

Doxorubicin Loaded Gold Nanoparticles Mitigate Liver Fibrosis and Inflammatory Cytokines Gene Expression in Rat

BACKGROUND

Gold nanoparticles have the potential to be used as a carrier in drug delivery systems due to their small size, large surface area and short circulation time in blood.

OBJECTIVE

This study demonstrates that doxorubicin conjugation with gold nanoparticles (AuNPs) may reduce its toxicity as well as improve therapeutic efficacy.

METHODS

Five groups of Albino rats were used; 1: healthy control, 2: injured, 3: injured and treated with Dox, 4: injured and treated with AuNPs, 5: injured and treated with AuNPs: Dox. At the end of the experiment, blood and liver tissues were processed for biochemical and histopathological analysis. The expression of collagen, HO-1, IL-6 and TNF-α genes involved in liver fibrosis was observed through real-time PCR.

RESULTS

At the end of the experiment, it was observed that the body weights of DOX-treated rats decreased by 0.72%, however, AuNPs and Au: DOX-treated rats were 15.3% and 29.13% respectively. The percentage of liver protection determined through alanine aminotransferase and aspartate aminotransferase levels in DOX, AuNPs and AuNPs: DOX treated groups were 39.21%, 79.26%, 98.17% and 47.77%, 84.17%, 97.92%, respectively, representing better recovering liver in Dox-AuNPs treated rats compared to others. Histopathological and gene expression studies further support the findings. The mRNA expression levels of inflammatory and oxidative stress-related genes HO-1, IL-6 and TNF- α were upregulated in the injured group but downregulated in the treated group.

CONCLUSION

As depicted through biochemical, histopathological and gene expression studies, Au: DOX conjugate group seems to be protective against liver fibrosis.

Recent Advances in the Treatment of Bone Metastases and Primary Bone Tumors: An Up-to-Date Review

In the last decades, the treatment of primary and secondary bone tumors has faced a slow-down in its development, being mainly based on chemotherapy, radiotherapy, and surgical interventions. However, these conventional therapeutic strategies present a series of disadvantages (e.g., multidrug resistance, tumor recurrence, severe side effects, formation of large bone defects), which limit their application and efficacy. In recent years, these procedures were combined with several adjuvant therapies, with different degrees of success. To overcome the drawbacks of current therapies and improve treatment outcomes, other strategies started being investigated, like carrier-mediated drug delivery, bone substitutes for repairing bone defects, and multifunctional scaffolds with bone tissue regeneration and antitumor properties. Thus, this paper aims to present the types of bone tumors and their current treatment approaches, further focusing on the recent advances in new therapeutic alternatives.