DNA Double-Strand Breaks in Murine Mammary Tumor Cells Induced by Combined Treatment with Doxorubicin and Controlled Stable Cavitation

Recent Advances in Kaolinite Nanoclay as Drug Carrier for Bioapplications: A Review

Advanced functional two-dimensional (2D) nanomaterials offer unique advantages in drug delivery systems for disease treatment. Kaolinite (Kaol), a nanoclay mineral, is a natural 2D nanomaterial because of its layered silicate structure with nanoscale layer spacing. Recently, Kaol nanoclay is used as a carrier for controlled drug release and improved drug dissolution owing to its advantageous properties such as surface charge, strong biocompatibility, and naturally layered structure, making it an essential development direction for nanoclay-based drug carriers. This review outlines the main physicochemical characteristics of Kaol and the modification methods used for its application in biomedicine. The safety and biocompatibility of Kaol are addressed, and details of the application of Kaol as a drug delivery nanomaterial in antibacterial, anti-inflammatory, and anticancer treatment are discussed. Furthermore, the challenges and prospects of Kaol-based drug delivery nanomaterials in biomedicine are discussed. This review recommends directions for the further development of Kaol nanocarriers by improving their physicochemical properties and expanding the bioapplication range of Kaol.

Mechanical force induced DNA double-strand breaks: Ultrasound

Since the application of ultrasound for clinical diagnosis and therapeutic purposes has been increased rapidly, the effects of exposure to ultrasound on DNA molecules were studied. In this chapter, we introduced various effects of DNA damages caused by different conditions of exposure of ultrasound. Ultrasound with different sound pressure and pulse transmission conditions have been applied in our study. We discussed the threshold of sound pressure of ultrasound-induced DNA damages. Different kinds of pulses of ultrasound and microbubbles' influences on DNA double-strand breaks were also shown.

Magnetic Nanoparticles: Current Advances in Nanomedicine, Drug Delivery and MRI

Magnetic nanoparticles (MNPs) have evolved tremendously during recent years, in part due to the rapid expansion of nanotechnology and to their active magnetic core with a high surface-to-volume ratio, while their surface functionalization opened the door to a plethora of drug, gene and bioactive molecule immobilization. Taming the high reactivity of the magnetic core was achieved by various functionalization techniques, producing MNPs tailored for the diagnosis and treatment of cardiovascular or neurological disease, tumors and cancer. Superparamagnetic iron oxide nanoparticles (SPIONs) are established at the core of drug-delivery systems and could act as efficient agents for MFH (magnetic fluid hyperthermia). Depending on the functionalization molecule and intrinsic morphological features, MNPs now cover a broad scope which the current review aims to overview. Considering the exponential expansion of the field, the current review will be limited to roughly the past three years.

Establishing and characterizing a novel doxorubicin-resistant acute myeloid leukaemia cell line

Drug resistance is a major setback in cancer treatment, thus models to study its mechanisms are needed. Our work aimed to establish and characterize a resistant cell line from a sensitive acute myeloid leukaemia (AML) cell line - HL60 - by treating the sensitive cells with increasing concentrations of doxorubicin. We confirmed (cell viability assays) that the established subline, HL60-CDR, was resistant to doxorubicin for at least 30 days without drug treatment. The HL60-CDR cells were also resistant to three other drugs (cisplatin, etoposide and daunorubicin), exhibiting a multidrug resistant (MDR) profile. We verified (Western Blotting) that the MDR cells do not express drug efflux pumps, nor present altered expression of apoptotic proteins, when compared with the parental cell line. HL60-CDR cells presented alterations in the cell cycle profile, and in the expression levels of proteins involved in DNA repair mechanisms and drug metabolism, when compared with their drug sensitive counterpart. Proteomic analysis revealed that HL60-CDR cells presented an upregulation of proteins involved in oncogenic pathways, such as TSC2, PDPK1, Annexin A2, among others. Overall, we established an AML MDR subline - HL60-CDR - which presents several resistance mechanisms, providing an in vitro model to test new compounds to circumvent MDR in AML.

Ultrasound-Induced DNA Damage and Cellular Response: Historical Review, Mechanisms Analysis, and Therapeutic Implications

The biological effects of ultrasound may be classified into thermal and nonthermal mechanisms. The nonthermal effects may be further classified into cavitational and noncavitational mechanisms. DNA damage induced by ultrasound is considered to be related to nonthermal cavitations. For this aspect, many in vitro studies on DNA have been conducted for evaluating the safety of diagnostic ultrasound, particularly in fetal imaging. Technological advancement in detecting DNA damage both in vitro and in vivo have elucidated the mechanism of DNA damage formation and their cellular response. Damage to DNA, and the residual damages after DNA repair are implicated in the biological effects. Here, we discuss the historical evidence of ultrasound on DNA damage and the mechanism of DNA damage formation both in vitro and in vivo, compared with those induced by ionizing radiation. We also offer a commentary on the safety of ultrasound over X-ray-based imaging. Also, understanding the various mechanisms involved in the bioeffects of ultrasound will lead us to alternative strategies for use of ultrasound for therapy.

Proof of Concept: Protein Delivery into Human Erythrocytes Using Stable Cavitation

Human erythrocytes represent candidates of choice as carriers for a wide range of drugs due to their unique biophysical and physiological properties. In this study, we used a sonoporation device generating and monitoring acoustic stable cavitation without any addition of contrast or nucleation agents. The device was evaluated for bovine serum albumin (BSA) delivery into human erythrocytes. After determining the adequate hematocrit percentage compatible with the generation of stable cavitation, we determined the optimal sonoporation conditions allowing BSA delivery while preserving erythrocyte integrity. Our results demonstrate that stable cavitation allows efficient delivery of proteins into human erythrocytes with limited lysis of these cells. In conclusion, our study allowed for the development of a stable and regulated cavitation program and the establishment of sonoporation conditions suitable for intracellular protein delivery while maintaining erythrocyte integrity. Additional investigations are needed to move from the proof of concept to a larger-scale application.