Nanotechnology-based Delivery Systems Research Articles

Targeting of nanoparticles in cancer

Anticancer agents continue to be a preferred therapeutic option for several malignancies. Despite their effectiveness, oncologists are continually looking for tumor-specific anticancer agents to prevent adverse effects in patients. Targeting of imaging agents to cancerous tissue is another area that is enthusiastically explored to circumvent some of the drawbacks that current imaging agents possess, including the inability to target small tumor cells, inadequate imaging period, and the risk of renal damage. Formulation scientists have explored nanotechnology-based delivery systems for targeting anticancer agents and tumor-imaging agents to cancer tissue. Targeting with nanotechnology-based delivery systems has been investigated by both passive and active mechanisms with significant clinical success. This review presents a discussion on targeting strategies used for the delivery of nanoparticles by passive and active mechanisms, focusing more specifically on active targeting of nanoparticles using albumin, folic acid, transferrin, and aptamers as targeting ligands.

Permeability Variation Study in Collagen-Based Polymeric Capsules

Nanomedicine, the application of nanotechnologies to healthcare, is an area of nanotechnology which is promising and has extraordinary and far-reaching implications on human health both from the points of view of disease diagnosis and treatment. With regard to disease treatment, the possibility of developing new nanosystems for efficient drug delivery has attracted great attention. A prerequisite for nanotechnology-based delivery systems, in order to be effective, is that the encapsulated drug molecules have to be released at the site of interest. One method to obtain specific release is based on the development of systems sensitive to disease-associated overexpressed enzymes. In this study, we report on the fabrication of collagen-based containers for drug encapsulation and release by cellular demand by the action of the collagenolytic enzymes matrix metalloproteinases (MMPs).Collagen is the major component of the connective tissue and is involved in many biological functions. Its degradation is at the basis of different pathological processes. The up-regulated expression of MMPs is the cause of such degradation. Collagen-based capsules were fabricated by the layer-by-layer technique and characterized by scanning electron microscopy and confocal microscopy. Real-time monitoring of the release kinetics of loaded gold nanoparticles, having different diameters, was done by total reflection X-ray fluorescence. Excitation of the fluorescence was performed by grazing incidence X-ray beam of synchrotron radiation. This study represents the first attempt in estimating the distribution and dimension of pore size in polyelectrolyte nanoshells.

Insights into the novel three ‘D's of epilepsy treatment: drugs, delivery systems and devices

Here, we review three 'D's--drugs, delivery systems and devices--that can selectively target not only brain regions but also abnormal cells in the epileptic nervous system. This review also offers insights into the novel molecular targets that enabled the development of new antiepileptic drugs with improved efficacy. Nanotechnology-based delivery systems and alert, diagnostic, surgical and brain stimulation devices designed for the control and management of epilepsy are also discussed. Although the application of the three 'D's continues to be valuable, this review also considers computer-aided software systems, with special emphasis on seizure detection and management. Finally, challenges that still loiter in the field and future prospects that, once accomplished, could lead to cures for epilepsy are addressed.

Cyclin-dependent kinase-5 targeting for ischaemic stroke

Recovery from ischaemic stroke is dependent on survival of neurones, particularly in peri-infarcted regions. Angiogenesis is critical for the development of new microvessels resulting in the re-formation of collateral circulation associated with enhanced neuronal survival and reduced morbidity and mortality. Recently, the identification of a neurovascular niche has been described, where the co-ordinated effects of angiogenesis and migration of neuroprogenitor cells to damaged stroke regions were shown to be vital in the process of tissue remodelling. Cdk5, a serine/threonine kinase is highly expressed in the central nervous system, particularly following ischaemic stroke and its aberrant activation is directly associated with neuronal apoptosis and death. In contrast, recent evidence suggests that increased expression of Cdk5 by endothelium might be protective against cell death and/or promote angiogenesis leading to increased vessel formation and reperfusion. Owing to its known interaction with over 20 substrates including caspase-3, MEF2, Tau and p53, Cdk5 could be a master switch controlling both neuronal survival and revascularisation. Therefore its cell-specific pharmacological or genetic modulation using novel nanotechnology-based delivery systems could be of benefit when considering future stroke therapies.

Nanotechnology-Based Delivery Systems in Hiv/Aids Therapy

The therapeutic efficacy of anti-HIV agents is often hampered by poor bioavailability and lack of drug penetration in infected target tissues and cells. Using different types of nanotechnology-based delivery systems, it is possible to engineer strategies that can improve the therapeutic efficacy in HIV/AIDS by delivering drugs to cellular and anatomical viral reservoirs. The rationale for the use of nanocarrier systems relies on the fact that different types of therapeutic payloads can be encapsulated and the systemic pharmacokinetics and distribution are dictated by the properties of the nanocarriers rather than the drugs. The versatility of nanoplatforms can be further exploited in a formulation that has enhanced oral bioavailability, protects against degradation upon oral or systemic administration and prolongs the residence time at the target site. Nanocarriers can facilitate lymphatic transport, delivery across the blood–brain barrier, and efficient internalization in cells by nonspecific or receptor-mediated endocytosis. In this review, we will address the role of nanotechnology-based delivery systems in improving the delivery efficiency of anti-HIV drugs to cellular and anatomical sites of interest. Specific published examples will be highlighted with emphasis on the role of polymeric nanoparticle micelles, liposomes and nanoemulsions in improving delivery efficiency.