ARTIFICIAL BREAST

This subject was studied in relation to the silicone breast implant controversy of the 1990s. Silicone-fiUed artificial breasts were coated with thin layers of a TDI-based polyurethane foam to encourage stabilization by cell ingrowth. Residual toluene diamine (TDA) was found in prepolymer-based polyurethanes at the part-per-biUion level and, more importantly, hydrolysis that would lead to the release of more TDA in vivo was suspected. 

Artificial breast implants require a flexible rather than a strong material hence, the use of synthetic hydrogels seems appropriate. However, the material actually used is not a hydrogel but a silicone elastomer with zero water content. Using this hydrophobic material, a bag is made in which a silicone gel or saline solution is filled. From the mechanical point of view, a hydrogel could be used as a breast implant. However, it is not used because of the possibility of calcination by diffusion of Ca ++ or PO . This is not a concern with hydrophobic gels. It is possible, however, that fat might diffuse into the silicone gel. 

Section 2 Applications of Gel for Plastic Surgery Artificial Breasts and Skin... 

Delaunay-El AUam, M., Marlier, L., and Schaal, B. (2006). Learning at the breast preference formation for an artificial scent and its attraction against the odor of maternal milk. Infant Behav. Dev. 29, 308-321. 

The first ever injectable crude biomaterial, that is a dental implant, appeared early in ad 6oo (Fig. 12.1). During those times, Mayan people trimmed seashells into artificial teeth to replace missing teeth (Michael, 2006 Ratner et al., 2004). Early biomaterials also led to problems, including sterilization, toxicity, inflammation, and immunological issues. Since the Mayan s initial use of artificial teeth, biomaterials have evolved to be used in modem artificial hearts, hip and knee pros-theses, artificial kidneys, and breast implants. Materials used in these applications include titanium, silicons, polyurethanes, teflon, polybiodegradable polymers, and most recently bio-nanomaterials (Pearce et al., 2007)... 

In the biomedical area, SPHs and SPH composites can be used to make various biomedical devices, such as artificial pancreas, artificial cornea, and artihcial skin, articular cartilage, soft tissue substitutes, cell growth substrates in tissue engineering, burn dressings, surgical augmentation of the female breast, or hemoperfusion in blood detoxification and in the treatment of uremia. 

Breast milk also safeguards against obesity and cancer. Several carefully designed studies have found that artificially fed infants go on to suffer significantly higher rates of Hodgkin s lymphoma than babies breastfed for six months or more. 

Mian S, Ball G, Hornbuckle J, et al. A prototype methodology combining surface-enhanced laser desorption/ionization protein chip technology and artificial neural network algorithms to predict the chemoresponsiveness of breast cancer cell lines exposed to Paclitaxel and Doxorubicin under in vitro conditions. Proteomics 2003 3(9) 1725-1737. 

Genetic selection for commercial turkey production has resulted in broad-breasted varieties that have rapid growth and high feed-conversion efficiency. The modem varieties have lost their natural ability to fly or forage for feed. Artificial insemination is routinely used with turkey breeders to avoid injury of the hens by the much larger toms and because the broad breasts have resulted in most males having a conformation that renders them incapable of natural mating. 

It has been stated that idiopathic hypercalcemia has not been known to develop in a wholly breast-fed infant (B6). Morgan et al. (M3), however, have described an infant who was still breast fed at the time of diagnosis at 8 months of age and whose intake of cow s milk consisted only of that present in puddings and other cereal foods. The association between artificial feeding and idiopathic hypercalcemia has been related to the fact that the calcium content of cow s milk is four times that of human milk. On the other hand the phosphorus content of cow s milk is also higher, and this has been suggested as a cause of hypocalcemia in infants (G2). 

A 29-year-old woman took citalopram (40 mg/day) while breast feeding her 5-week-old daughter. The maternal citalopram concentrations were 99 ng/ml in the serum and 205 ng/ml in the breast milk. The serum concentration in the infant was 13 ng/ml, and the child s sleep was fitful and disturbed. The dosage of citalopram was reduced to 20 mg/day and the two feeds after each daily dose were replaced by artificial nutrition. One week later the infant was sleeping normally, and the serum citalopram concentrations in mother and infant had fallen to 35 ng/ml and 2 ng/ml, respectively. 

Grulee C, Sanford H The influence of breast and artificial feeding on infantile eczema. J Pediatr 1936 72 411-414. (Ila)... 

Also mentioned in the aforecited book are colchicine and colchidnamide, derived from the common autumn crocus (Colchicum autumnale), also called meadow saffron. (Colchicine, incidentally, is used in plant gaieties to artificially produce mutations.) The notable use cited is against breast cancer, but gout and arthritis also yield to treatment. It is emphasized that both these alkaloids are potent, and their use requires expert medical supervision. Another plant mentioned is cro-talaria (Crotalaria spectabilis), from which a toxic alkaloid called monocrotaline may be obtained. This substance also has antitumor properties, but acts against the liver. 

The application of polymeric materials in medicine is a fairly specialized area with a wide range of specific applications and requirements. Although the total volume of polymers used in this application may be small compared to the annual production of polyethylene, for example, the total amount of money spent annually on prosthetic and biomedical devices exceeds 16 billion in the United States alone. These applications include over a million dentures, nearly a half billion dental fillings, about six million contact lenses, over a million replacement joints (hip, knee, finger, etc.), about a half million plastic surgery operations (breast prosthesis, facial reconstruction, etc.), over 25,000 heart valves, and 60,000 pacemaker implantations. In addition, over AO,000 patients are on hemodialysis units (artificial kidney) on a regular basis, and over 90,000 coronary bypass operations (often using synthetic polymers) are performed each year (]J. 

---