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Heritable breast cancer syndromes have identified the recognition and processing of DNA double strand breaks as a fundamental vulnerability in the breast epithelium. The role of homology-directed DNA repair is particularly prominent, indicating that this repair pathway is rate-limiting. Although the activities of the tumor suppressor genes underlying heritable breast cancer act in a common pathway of DNA double strand break repair, the specific lesions result in surprisingly different patterns of biomarkers in the breast cancers, suggesting that they arise from different cell types that include the luminal, basal and progenitor cells within the breast epithelium. Therefore, each cell type appears to have distinct underlying vulnerabilities in repair of DNA double strand breaks. While the heterogeneity of targets poses a challenge to develop specific therapies, these pathways also render tumor cells sensitive to drugs targeting double strand break repair pathways offering new options for therapies. As double strand break repair is a common pathway underlying breast cancer risk, therapies that enhance the proficiency of this pathway offer a strategy for chemoprevention.

The development of nanoscale delivery vehicles for siRNAs is a current topic of considerable importance. However, little is understood about the exact trafficking mechanisms for siRNA-vehicle complexes across the plasma membrane and into the cytoplasm. While some information can be gleaned from studies on delivery of plasmid DNA, the different delivery requirements for these two vehicles makes drawing specific conclusions a challenge. However, using chemical inhibitors of different endocytosis pathways, studies on which endocytotic pathways are advantageous and deleterious for the delivery of nucleic acid drugs are emerging. Using this information as a guide, it is expected that the future development of effective siRNA delivery vehicles and therapeutics will be greatly improved.

Genomic modification through nucleic acid delivery is a frequently applied method in fundamental biological studies and offers a potent therapeutic strategy for disease treatment and biological research. Delivery of nucleic sequences is therefore an attractive facet of biological nanotechnology as highly specific, efficient, and nonantagonistic delivery is necessary for in vivo and clinical use. Previous vectors have suffered from immunogenic responses, serum dependent inactivation, and cytotoxicity, hindering their translational applicability. Current research in polymeric-based nucleotide delivery strives to offer a highly biocompatible, broad use vector through the utilization of polypeptide and polyamine conjugation that can be easily tailored for specific targeting or wide dissemination. Cross-linking low molecular weight polyamines and lipophilic derivatization for amphiphile creation has lead to improved biocompatibility and transfection efficiency compared to higher molecular weight polyamines. Derivatization of hyperbranched and dendritic polyamido- and polyamines has allowed for the formation of efficient in vivo transfection vectors; ring opening synthesis of N-carboxyanhydride amino acids have led to controlled peptide architectures for improved transfection while simultaneously providing convenient primary amines useful in functionalization. Polymer libraries of poly(ß-amino esters) have provided insights into useful architectures for in vitro and in vivo gene delivery. Grafting small molecules to polyamines, such as folate and galactose, for enhanced interaction with cell surface receptors for selective targeting of specific cell types has proven to be encouraging and remains a prominent aspect in biological nanotechnology.

This review paper presents an overview of periodontal disease, beginning with clinical aspects including prevalence, etiology, disease progression mechanisms and implications for general health, followed by current diagnostic and therapeutic approaches. We then describe experimental models used for in vitro and in vivo investigations of periodontal disease, and emerging therapeutic approaches based on biomedical and tissue engineering concepts, nanotechnology, gene and stem cell therapies. We aim to provide bioengineers, tissue engineers and nanotechnology researchers an overall understanding of the state-of-the-art of periodontal disease to foster technological innovation based on interdisciplinary research and collaboration between physical and medical scientists.

Chemotherapy and other traditional anticancer treatments are losing their efficacy in the battle against cancer. As a result, cancer treatment strategies must be continually adjusted to meet the rising demand for alternative medicines. Several viral and non-viral vectors have been used previously. However, it has been shown that microorganisms are a strong contender for successfully combating cancer. They are a remarkable source of toxins, polysaccharides, tumor-specific anticancer genes, nanodrugs and gene-delivery vectors. One of the emerging key players in cancer therapy is bacteria. It has been demonstrated that traditional methods of altering the microbiome, such as antibiotics, probiotics and microbiota transplants, can sometimes increase the effectiveness of cancer therapies. However, problems with these methods, such as consistency and collateral damage to the commensal microbiota, spur the development of new technologies specifically aimed at the microbiome-cancer interface. In light of nanotechnology’s success in transforming cancer diagnostics and treatment, nanotechnologies with the capacity to control interactions that occur across microscopic and molecular length scales in the microbiome and the tumor microenvironment have the potential to provide innovative methods for cancer treatment. The relationship between nanotechnology, the microbiome and cancer offers tremendous potential. This paper highlights the contributions of significant bacterial groups to several anticancer research fields.