No abstract

Alzheimer’s disease (AD) is a neurodegenerative disease, which affects millions of people worldwide. Curing this disease has not gained much success so far. Exhaled breath gas analysis offers an inexpensive, noninvasive, and immediate method for detecting a large number of diseases, including AD. In this paper, a new method is proposed to detect butylated hydroxytoluene (BHT) in the air, which is one of the chemicals found in the breath print of AD patients. A three-layer sensor was formed through deposition of a thin layer of graphene onto a glassy carbon substrate. Selective binding of the analyte was facilitated by electrochemically initiated polymerization of a solution containing the desired target molecule. Subsequent polymerization and removal of the analyte yielded a layer of polypyrrole, a conductive polymer, on top of the sensor containing molecularly imprinted cavities selective for the target molecule. Two sets of sensors have been developed. First, the graphene sensor has been fabricated with a layer of reduced graphene oxide (RGO) and tested over 5–100 part per million (ppm). For the second batch, Prussian blue was added to graphene before polymerization, mainly for enhancing the electrochemical properties. The sensor was tested over 0.02-1 parts per billion (ppb) level of concentration while the sensor resistance has been monitored.

Restoration of articular hyaline cartilage within osteochondral tissue defects has been a principal target in the field of tissue engineering due to poor functional regeneration of this avascular and heterogeneous tissue following current treatment options. The major focus thus far has been in constructing implantable scaffolds, which can be readily designed to offer appropriate mechanical properties. However, the use of implantable scaffolds requires open surgery and often cannot be readily applied to defects of irregular shape. Thus, it has become of high interest to develop minimally invasive and degradable hydrogel-based materials capable of delivering and maintaining encapsulated cells in a non-toxic manner and encouraging functional tissue regeneration. This paper reports on the synthesis and characterization of a novel class of injectable, thermally and chemically dual-gelling bionanocomposite hydrogels from thermogelling macromers (TGMs) based on poly(N-isopropylacrylamide) (pNiPAAm), degradable polyamidoamine (PAMAMs) crosslinking macromers, and functional hybrid inorganic iron oxide (Fe 3 O 4 ) nanoparticles capable of responding to an external magnetic field to stimulate cell activity and control the regenerative process in situ in a spatiotemporal manner.

No abstract