Lecture 15: Stealth' particles Last time Nano- and micro-particle carriers Today Delivery of drugs to tissue from circulation stealth particles theory and function Reading S. Stolnik et al. 'Long circulating microparticulate drug carriers, Adv. Drug. Deliv. Rev 16,195(1995) Delivery of drugs to tissues via systemic circulation

Lecture 19: Biosensors(continued ast time: biosensor device cla Gene array biosensor Today detection methods Detection Elements Macroscopic fluorescence, diffraction, or interference ·what Example: quantum dot-loaded microsphere capture agents QDs show size-dependent luminescence Narrow emission bands from a common excitation wavelength

Lecture 16: Intracellular drug delivery Last time nano- and micro-particle drug carriers Delivery to tissues from systemic circulation Today. Intracellular drug delivery Reading A.S. Hoffman et aL., Design of \smart polymers that can direct intracellular drug delivery, Polym. Adv. Technol. 13, 992-999(2002) Ph gradients and drug delivery: cancer res. 56, 1194(1996): adv drug deliv rev 25, 3 (1997); see asokan minireview

2.4.1 Cell Activities \Packaged\ sequences (cascades) of cell activities/functions with an identifiable beginning and an end 2.4.1.1 Mitosis(Proliferation) Mitosis is a complex of processes leading to the division of a cell such that the two daughter nuclei receive identical complements of the number of chromosomes characteristic of the cells of the species. All cells arise from the division of pre-existing cells. The process of mitosis is divided into four phases:

molecular switches Proteins as motors in nanodevices Today. nano-and micro-particle drug carriers Reading D A Hammer and D.E. Discher, ' Synthetic cells- Self-assembling polymer membranes and bioadhesive colloids, Annu. Rev. Mater Res, 31, 387-404 (2001) Nano- and Micro-scale Drug Carriers and Detection Reagents Nano- to Micro-particle polymer-protein

TISSUE Tissue is a biological structure made up of cells of the same type. - Cells of the same phenotype(e., same genes expressed). An aggregation of morphologically similar cells and associated extracellular matrix acting together to perform one or more specific functions in the body. - There are four basic types of tissue: muscle, nerve, epithelia, and connective. An organ is a structure made up of or more tissues

Molecular switches in the cell: fibronectin as a mechanical switch (vogel, 2002) Fibronectin is an adhesion protein secreted by cells and assembled into fibrils to support adhesion and migration Composed of\ of fibronectin repeats Fnl, Fnll, and Fnlll connected by short linkers of varying flexibility One particular Fnlll repeat, Fnlll10

Lecture 9: Polyelectrolyte Hydrogels Last Day: Physical hydrogels Structure and chemistry Toda polyelectrolyte hydrogels, complexes, and coacervates rolyte multilayer theory of swelling in ionic hydrogels Reading S.K. De et aL., 'Equilibrium swelling and kinetics of pH-responsive hydrogels: Models experiments, and simulations

Lecture 3: Degradable Materials with Biological Recognition Last time: Theory of hydrolytic polymer erosion Enzymatic degradation of polymers Designing Biodegradable Macromolecules Today: Biological recognition in vivo Engineering biological recognition of biomaterials: cell adhesion/migration Reading: S.E. Sakiyama-Elbert and J.A. Hubbell, 'Functional Biomaterials: Design of Novel

Brannon-Peppas theory of swelling in ionic hydrogels Original theory for elastic networks developed by Flory and Mehrer, refined for treatment of ionic hydrogels by Brannon-Peppas and Peppas Other theoretical treatments Derivation of ionic hydrogel swelling Model structure of the system