Search

Continuous replacement of teeth throughout the lifespan of an individual is possibly basal for most of the vertebrates including fish and reptiles; however, mammals generally have a limited capacity of tooth renewal. The ability to induce cellular differentiation in adults to replace lost or damaged cells in mammals, or to tissue-engineer organs in vitro, has hence become one of the major goals of regenerative medicine. In this article, we will revisit some of the important signals and tissue interactions that regulate mammalian tooth development, and will offer a synopsis of the latest progress in tooth regeneration and repair via molecular and engineering approaches. It is hoped that this article will not only offer an overview of recent technologies in tooth regeneration and repair but will also stimulate more interdisciplinary research in this field to turn the pursuit of tooth regeneration and repair into practical reality.

Protein kinases are enzymes that catalyze the transfer of γ phosphate from adenosine triphosphate to substrate proteins, and are important signal transduction mediators in a diversity of biological processes, ranging from apoptosis to energy metabolism. In this article, we will take this prominent class of proteins as an example to illustrate the involvement of proteins in modulation of aging and to highlight the prospects and challenges of protein-targeted interventions for anti-aging purposes. It is hoped that through this article, more empirical work on interventive gerontology will follow, and with collaborative endeavors among researchers, hurdles in anti-aging intervention development can be overcome in the near future.

This study sought to investigate, with a focus on the Hong Kong context, how commercial slimming websites portray the body image of beauty to the public, and to explore practical implications for related public health practices and health policy formulation. Commercial entities in the Hong Kong slimming industry were retrieved from the Hong Kong Yellow Page Directory and Yahoo Hong Kong Directory, and selected websites were coded and further analyzed. We found that irresponsible tactics are used in the slimming industry such that irresponsible messages prevail. Collaborative efforts from multidisciplinary sectors are needed to tackle the situation.

Pursuance of longevity is not only combating decrepitude but it is also extending the health span; otherwise longevity would result in a universal medical and social burden. As revealed by the literature, the attainment of a healthy life could be impacted by the social milieu. An inquiry of this kind could hardly be settled by mere laboratory endeavors, and thus serious discussion of the social dimension of life span extension is imperative. However, little attention has been paid to this need in the biogerontological field. In view of this gap, the aim of this article is to explore the health relationship of the social milieu by using social relations as an example and to raise the awareness within our biogerontological community of the relevance of the social milieu to our existing efforts on longevity pursuance. It is hoped that through this article and with the success of antiaging therapies, not only could collaborative work between biogerontologists and scholars in other disciplines be stimulated, but indefinite extension of both life span and health span could also be achieved in the future.

Chitosan is generally biocompatible, biodegradable, mucoadhesive, non-toxic and non-immunogenic. Even though it has been shown to be able to condense nucleic acids (NA) (both DNA and RNA) and to protect them from nuclease degradation, its poor water solubility and low transfection efficacy have impeded its use as a gene carrier. On the other hand, high molecular weight polyethylenimine (PEI) (Mw = 25kDa) is generally deemed efficient in transfection, but its high cytotoxicity makes it not a suitable vector in vitro. In order to fabricate a polymer with the merit of low toxicity of chitosan and high transfectability of PEI, we have conjugated chitosan with low molecular weight non-toxic PEI (MW= 0.8kDa and 1.3kDa) with a coupling reagent-mediated approach. We found that the resultant products (CP0.8K and CP1.3K) not only exhibited low cytotoxicity in vitro, but also showed high transfectability in a panel of cell lines (B16-F1, U87, C666-1 and HeLa). Our results indicate that CP0.8K and CP1.3K have great potential as gene carriers in vitro, in vivo or even clinically.

Technologies for nucleic acid delivery have displayed high practical potential in mediating genetic manipulation to modulate metabolic pathways to combat aging. In the previous chapter, we have delineated a series of techniques for designing and developing polymeric vectors as nonviral carriers. Based on what we have discussed, this chapter will introduce how the delivery performance and versatility of polymeric vectors can be further enhanced by using cyclodextrins (CDs). Over the years, CDs have shown promising application potential in different areas, ranging from controlled drug release to chiral separation of basic drugs. These applications are largely mediated by the ability of CDs to undergo host–guest inclusion complexation. Upon incorporation of CDs into the design of a polymeric vector, not only can the flexibility of the design be increased, but the development of a multifunctional carrier for genetic manipulation can also be facilitated.

Anti-aging medicine has become a popular topic in recent years. It considers biological aging a revertible process that physiologically serves no posi tive function. Different technologies in systemic delivery and various strategies that characterize and optimize the performance of systemic delivery have been covered in this book. These technologies are essential for the establishment of a technical platform for interventive biogerontology. As the last chapter of this book, we would like to highlight some directions for future applications of systemic drug delivery in anti-aging medicine. We believe that biological aging and aging-related diseases are strongly associated with genetics/genomics and are pre-programmed. Several interventive approaches such as cellular/tissue reprogramming, microbiota supple mentation, seno-therapeutics and pharmacological targeting will be discussed in this chapter