Disadvantages of Polymeric Nanoparticles
Although polymeric nanoparticles have many advantages such as various fabrication methods, versatile drug loading, and drug release methods , they still have some drawbacks. The main limitation is that some preparation methods use toxic organic solvents that could degrade certain drugs when they come into contact during the formulation process or could be hazardous to the environment as well as to the physiological system Birnbaum et al. 2000 . Other disadvantages include poor drug...
Quantum Dots in Cancer Imaging and Treatment 521 Active and Passive Targeting
Having superior light-emitting properties, QDs are excellent candidates for tumor imaging if they can be effectively delivered to tumor sites. Both passive and active targeting mechanisms are being aggressively pursued in order to achieve this goal. Numerous studies have reported methods to lengthen circulation time of QDs in the blood and target QDs to cancerous tissues Gao et al. 2004a kerman et al. 2002 Rosenthal et al. 2002 . Coating QDs with polymers such as PEG to avoid uptake by the RES,...
Liposomes and their Advantages in Drug Delivery
Liposomes are spherical, self-closed vesicles formed by one or several concentric lipid bilayers with an aqueous phase inside and between the lipid bilayers Fig. 3a . Therefore, liposomes usually have hydrophilic outer surfaces, hydrophilic inner cores, and hydrophobic matrices in between. Figure 3b gives an example of a transmission electron microscope TEM image of liposomes adapted with permission from reference Ran et al. 2002 . There are several advantages of using liposomes for drug...
Bone Marker Biosensors
Bone marker sensing and correlation with bone regeneration have attracted much attention in recent decades Yun et al. 2007 . The development of electronic biosensors to detect bone markers in solutions has been reported Yun et al. 2009 . Briefly, a label-free immunosensor for bone maker detection in solutions outside the body has been tested. A self-assembled monolayer SAM of dithiodipropi-onic acid was deposited on a gold electrode. Then, a streptavidin biotinylated antihuman C-terminal...
Conductive and Piezoelectric Materials
Piezoelectric Aebischer et al. 1987 materials have also been shown to enhance neural cell function without any external electrical stimulation. Conductive polymers, typically PPy, have been shown to be a permissive substrate for axonal growth in vitro and in vivo. However, studies have shown that an electrical stimulus applied to the conducting polymer was needed to enhance axon outgrowth to levels beyond that which would be expected on an inert, biocompatible polymer Schmidt et al. 1997 Zhang...
Carbon NanotubeBased Orthopedic Implant Sensors
Abstract In this chapter, the use of multiwalled carbon nanotubes MWCNTs as sensors for healthy bone growth will be discussed. MWCNTs are cytocompat-ible with osteoblasts bone-forming cells and enhance osteoblast calcium deposition, and thus, bone formation. Moreover, here, MWCNTs have been grown out of nanopores of anodized titanium MWCNT-Ti , which has a surface layer of titanium oxide a popular chemistry for orthopedic implants , to serve as a novel in situ orthopedic implant sensor. The...
Repair Strategies in the PNS
While damaged tissue in the PNS is able to spontaneously regenerate after injury, the regeneration rate is quite slow. Axonal growth rates have been estimated at about 0.5-1 mm day Archibald et al. 1995 . Although those growth rates may translate into the bridging of a several millimeter nerve gap in a matter of days, reinnervation of target tissue can take months. Accelerating recovery is desirable due to the loss of function prior to appreciable tissue regeneration. The slow growth of axons...
Piezoelectric Nanomaterials
The next generation of biomaterials should include combinations of the above known stimulatory cues. Conductive or piezoelectric nanomaterials may elicit superior regenerative response compared to conductive, piezoelectric, or nanoscale materials alone. To date, few studies have combined nanomaterials with such known stimulatory electrical cues. An electrical stimulus may be incorporated into a nanomaterial scaffold by selecting a material that is piezoelectric. Ceramics, such as zinc oxide ZnO...
Electrically Active Neural Biomaterials
Justin T. Seil and Thomas J. Webster Abstract Numerous biomaterials have provided promising results toward improving the function of nervous system tissue. However, significant hurdles, such as delayed or incomplete tissue regeneration, remain toward full functional recovery of peripheral and central nervous system CNS tissue. Because of this continual need for better nervous system biomaterials, more recent approaches to design the next generation of tissue engineering scaffolds for the...
Wireless Medical Monitor Advantages and Disadvantages The Concept
There are two essential categories of wireless medical devices 1 wireless medical monitors and 2 wireless medical devices. Differences between these categories involve whether the devices only monitor health or also treat a medical problem. Wireless physiological measurements have a number of advantages over wired measurements, including ease of use, reduced risk of infection, reduced risk of failure, reduced user discomfort, enhanced mobility, and lower cost of care delivery Fig. 1 An...
Monitoring Tissue Healing Through Nanosensors
Abstract Nanotechnology is the use of materials with at least one dimension less than 100 nm. Nanotechnology has already revolutionized numerous fields, from construction to computers. Recently, nanotechnology has also been used to improve disease detection and treatment by developing wireless in situ sensors. Importantly, the use of wireless technologies in medicine, such as wireless body area networks and wireless personal area networks, is not new as they provide many promising applications...
Disadvantages of SPMNPs
In spite of the very exciting properties SPMNPs can offer, there are still several problems associated with using these nanoparticles in cancer diagnostics and therapeutics, especially for magnetically targeted drug delivery Lubbe et al. 1999 . The first limitation lies in the use of magnets for attracting superparamagnetic particles. When dealing with the tumors which have a large distance to possibly position the magnets, magnetic field strength at the tumor site will not be enough to attract...