Volume 3, Issue 6

Critical-sized bone defects have, in many cases, posed challenges to the current gold standard treatments. Bioactive glasses are reported to be able to stimulate more bone regeneration than other bioactive ceramics; however, the difficulty in producing porous scaffolds made of bioactive glasses has limited their extensive use in bone regeneration. On the other hand, calcium phosphate ceramics such as synthetic hydroxyapatite and tricalcium phosphate are widely used in the clinic, but they stimulate less bone regeneration. This paper gives an overview of the recent developments in the field of bioactive nanoparticles, with a focus on nanohydroxyapatite and bioactive glasses for bone repair and regeneration. First, a brief overview of the chemical structure and common methods used to produce synthetic nanohydroxyapatite and bioactive glasses has been presented. The main body of the paper covers the physical and biological properties of these biomaterials, as well as their composites with biodegradable polymers used in bone regeneration. A summary of existing challenges and some recommendations for future directions have been brought in the concluding section of this paper.

The well-known concept of electrical charging for the stabilization of colloidal solutions is extended to a general concept for explanation of behavior of nanoparticles during their formation, in their response behavior on chemical or electrochemical stress, and in particle/particle interactions. This concept helps to understand the formation of polynuclear sphere-like plasmonic nanoparticles of gold, the surprising high stability of extended flat silver nanoprisms, and their switch-like transformation as well as the formation of special types of nanoparticle assemblies. It can be used for controlling the size of nanoparticles, for the synthesis of composite micro and nanoparticles, and for the generation of different classes of nonspherical polymer particles by particle/particle interactions during the process of particle growth. The reported experimental examples were mainly obtained by microfluidic experiments, which supplied a high homogeneity of the product particles. This high homogeneity is an excellent basis for studying the nanoparticle behavior in analogy to molecular processes and helps to get new insights in to the importance of electrical effects for nanoparticle synthesis and nanoparticle assembling.

DNA nanoparticles (DeNAno) produced by rolling circle replication of circular oligonucleotide templates are a novel format for the selection of cell-binding reagents from randomized libraries. DeNAno particles consist of several hundred concatemers and can leverage that multivalency to bind to complex surfaces such as cells. In this study, an iterative bio-panning approach was used to recover particles that bound to the mouse pancreatic cancer line, Panc-02. These particles shared a primary sequence motif. Hybridization of a locked nucleic acid complimentary to this motif both inhibited cell binding and released pre-bound DeNAno particles from the cells. The monomeric form of one of the selected sequences was unable to compete with the cognate particle, consistent with a low-affinity, but high-avidity, type interaction. DeNAno library selection against cancer or other cell types can, thus, yield novel cell binding agents without a priori knowledge of particular cell surface molecules.

This study focuses on the encapsulation of natural curcumin present in turmeric ( Curcuma longa L.) into a layered double hydroxide (LDH), which demonstrates slow release properties with future potential in therapeutic applications such as slow release wound dressings. Turmeric has been used in traditional medicinal applications since ancient times. The main active substances in turmeric are curcumin together with two related compounds, demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC), which have been extensively studied as antibacterial compounds. However, these molecules are unstable and, therefore, demonstrate limited biological activity and practical applications. In this study, attempts were made to synthesize curcumin in-situ encapsulated layered LDHs in order to stabilize the curcumin molecules within the nanolayers of the LDHs. The curcumin intercalated LDHs were synthesized by a simple in-situ co-precipitation method. The release characteristics of curcumin from the nanocomposites were quantitatively monitored under different pH conditions using UV-Visible spectroscopic methods, and the results indicate that the nanocomposite has the future potential in slow release therapeutic applications.

The article is focused on the implementation of fluorescent silica nanoparticles in the laboratory curriculum. Along with a brief overview of experimental procedures appropriate for teaching in the laboratory and scarce examples of utilization of silica nanoparticles in the laboratory instruction, a new mini-laboratory course is described in detail. The series of the developed experiments allow the students to synthesize silica nanoparticles, place organic functionalities on their surface, and explore nanoparticles as labels and building blocks for nanoassemblies. Introduction of students to the art of using the most popular specific interaction in nanomedicine (avidin-biotin), along with synthesis and manipulation of nanoparticles, will help them bridge their existing or future knowledge of organic chemistry, materials science, and nanomedicine. The experiment is beneficial for students’ understanding of the relationship between organic chemistry, materials science, and nanomedicine, regardless of their level of expertise in those fields.

The America Invents Act (AIA) presents new challenges and strategy considerations for nanotechnology inventors and companies that seek to protect their intellectual property in the United States. Among the many notable changes, the AIA expands the “prior user rights” defense to infringement and broadens the classes of patents that are eligible for the new limited prior user rights defense. While this defense is limited in some instances, such as against universities, it could be invaluable in others, such as when a competitor independently discovers and patents the trade secret. In the world of nanotechnology, where inventions and products are increasingly complex, this protection can prove to be vitally important.