Recent Patents on Nanomedicine - Volume 3, Issue 2, 2013

Cancer is one of the leading causes of morbidity and mortality worldwide. Nanotechnology has offered intriguing potential to significantly improve the existing cancer diagnosis and treatment platforms. Recently, a variety of nanomaterials have emerged as promising tools for cancer therapeutic applications due to their unique structural, optical, magnetic, and electrical properties. The purpose of this review is to summarize the updated patents regarding the utility of nanomaterials for cancer treatment. In particular, this review will discuss several representative nanostructures, ranging from gold nanoparticles, polymeric nanoparticles, micelles and liposomes, magnetic nanoparticles, quantum dots and carbon nanotubes, and their applications in targeted drug delivery, radiotherapy, hyperthermia, photodynamic therapy, and photothermal therapy.

Nanotechnology has the potential to have a revolutionary impact on targeted cancer diagnosis and therapy. A major challenge in cancer diagnosis is to be able to non-invasively detect tumors at an early stage for maximum therapeutic benefit. In the development of effective therapeutic approaches, targeting and localized delivery are the key challenges. However, because many anticancer drugs are designed to simply kill cancer cells, often in a semi-specific fashion, the distribution of anticancer drugs in healthy cells and tissues is especially undesirable due to the potential for severe side effects. This review will address the state of the art in nanotechnologies, and their ongoing applications focused on addressing the challenges posed by the early detection and targeted treatment of cancer. Some relevant patents have also been discussed.

Early detection and treatment of diseases will increase the rate of cancer survival. Improving the performance of current diagnostic assay for cancer is in growing need. Recently, as potential diagnostic tools in the field of oncology, inorganic nanoparticles have received increased attention, which promises the promotion of in vitro cancer diagnosis toward new level of performance. Quantum dots (QDs), gold nanoparticles (AuNPs) and magnetic nanoparticles (MNPs) are the most promising nanomaterials for in vitro cancer detection. This mini-review surveys the issued patents in recent five years with the use of inorganic nanoparticles for diagnosing cancer.

Numerous efforts in oncological scientific research have revealed many causative facets of leukemia, explaining mechanistic aspects of disease progression at the molecular scale. Reports record over 40,000 new cases of patients afflicted with myeloid and lymphocytic leukemia annually worldwide. Early diagnosis and quick therapy are advantageous in effective treatment. Conventional methods mainly rely on blood cell counts and bone marrow biopsies for detection but these are inefficient in accurately diagnosing leukemia. Contemporary research has employed core nanotechnology in designing more efficient diagnostic and theranostic systems for leukemia. In such systems, biological markers and genetic materials such as siRNA and peptides tagged with nanoparticles (dendrimers, aptamers, and metal nanoparticles) form the fundamental elements that work at the molecular level and confer a high degree of specificity for recognition and capture, and in a therapeutic context, cytotoxicity for eradication of cancerous cells. We review current research and patented technologies that focus on nanomaterials as promising tools in detection and treatment of chronic and acute leukemia.

Traditional methods of drug delivery present several drawbacks, mainly due to off-target effects that may originate severe side and toxic effect to healthy tissues. Parallel to the development of novel more effective drugs, particular effort has been dedicated to develop and optimize drug delivery vehicles capable of specifically targeting the required tissue/organ and to deliver the cargo only where and when it is needed. New drug delivery systems based on nanoscale devices showing new and improved pharmacokinetic and pharmacodynamics properties like enhanced bioavailability, high drug loading or systemic stability have surged in the past decade as promising solutions to the required therapeutic efficacy. Amongst these nanoscale vectors, nanoparticles for drug delivery, such as polymeric, lipidbased, ceramic or metallic nanoparticles, have been at the forefront of pharmaceutical development. The interest in nanomedicine for treatment and diagnosis is clearly reflected on the increasing number of publications and issued patents every year. Here, we provide a broad overview of novel nanoparticle based drug delivery systems, ranging from polymeric systems to metal nanoparticles, while simultaneously listing the most relevant related patents.

The prevalence of new and re-emerging infectious diseases in many developing regions of the world indicates that we urgently need new-generation vaccines. Mucosal vaccine delivery systems have been shown to elicit both mucosal and systemic immune responses for protection against pathogens that mainly infect through mucosal routes. However, the efficacy of such vaccine delivery systems has been limited by mucosal barriers (e.g., pH and degrading enzymes) that limit the delivery of antigens to target tissues. However, although major challenges remain, various nanocarriers have been designed and developed, some of which confer the beneficial properties of nano-size, muco-adhesion, biodegradation, and immune cell-specific targeting; together, these characteristics enhance immunogenicity and prolong the retention time at the mucosal site. Furthermore, vaccination through novel mucosal routes has been shown to facilitate appropriate stimulation of immune responses for individual pathogens. Thus, in the future, various mucosal vaccine delivery systems may prove useful in clinical settings. In this review, we introduce recent advances in mucosal vaccine delivery systems and mucosal routes that are capable of enhancing mucosal immunity, with a focus on the relevant patent literature worldwide.

Past few decades have evidenced the extensive multidisciplinary investigation in the field of nanotechnology. Nanomedicines have emerged as promising carriers for delivery of diverse therapeutic molecules to the targeted sites. Owing to their unique physiochemical and optical properties, nanomedicines are used for multifunctional applications like delivery of therapeutic molecules, tumor targeting, imaging, etc. This present review mainly focuses on recent advancements, challenges and opportunities in the field of functionalized nanomedicines like liposomes, micelles, nanoparticles, and nanocomposites like nanotubes, graphenes and their derivatives for treatment of multiple types of cancers with special insight into the patent literatures. Also the nuances of the toxicological issues of the aforesaid nanosystems have been addressed.

Some self-assembling peptides form stable β-sheet structures and spontaneously self-assemble into nanofibers in water. To produce a stronger self-assembling peptide gel for use in nanomedicine, including drug delivery and tissue engineering, we designed peptides that formed covalent bonds among each other. We inserted the photolinker phenylalanine azide at the N terminus, center, and C terminus of the peptide monomer, and found that the peptide gel (PheN3-CT, H-DLRLDLALDLRLD-PheN3-OH) in the container had the smallest curvature of meniscus. Phenyl azide groups form short-lived nitrenes that might insert into the chemical bonds of N-terminal amino groups in neighboring peptides. The apparent diffusivity of phenol red in the gel made by the cross-linked peptide monomer PheN3-CT was almost the same as that of self-complementary peptides with 16 amino acids (RADA16, H-RADARADARADARADAOH). HEK293 cells and 3T3 myoblasts survived in gels containing PheN3-CT. These materials may have applications in the slow release of drugs and in three-dimensional scaffolds for use in mechanical physiological conditions. Some relevant patents have also been referred in this study.