nanobiomat t2

Describe gas foaming for porous scaffold fabrication

PLGA is saturated with co2 at high pressure, the solubility of the gas in the polymer is then rapidly decreased by bringing the co2 pressure back to atmospheric levels, resulting in nucleation and growth of gas bubbles with sizes ranging from 100-500 microns

Describe thermal induced phase separation scaffold fabrication

polymer is first dissolved in a solvent at high temperature, liquid-liquid liquid-solid phase separation is achieved by lowering the solution temperature. subsequent removal of the solidified solvent rich phase by sublimation leaves a porous polymer scaffold

describe SLA

builds 3d objects layer by layer using uv laser to selectively cure liquid photopolymer resin solidifying it into a desired shape

describe DLP

structure designed using cad, digitally sliced along the z direction into a series of images, uploaded onto dmd chip while 405 nm light projected onto it and reflected onto a motion controlled probe in photosensitive polymer resin probe moves upwards while light pattern changed based on series of uploaded images

describe mass transfer in static flasks

occurs via molecular diffusion no fluid flow at surface of construct

describe mass transfer in mixed flask

occurs due to convection fluid flow at surface is turbulent

describe mass transfer in rotating vessels

occurs due to convection due to settling fluid flow is laminar

describe mass transfer in perfused column and chamber

occurs due to convection due to recirculation fluid flow is laminar

what are the methods used for ordered nano topographies

photolithography electron beam lithography electrospinning

what are the methods used for unordered nanotopographies

polymer demixing phase separation electrospinning colloidal lithography chemical ethic self assembly

describe chemical etching

producing nanoscale features on the surface of a material by soaking it in etchant hydrofluoric acid sodium hydroxide

describe plasma etching

using plasma directly generating surface nanostructure

Woven fabrics with more _

regularly compartmentalized free spaces between the fibers

nonwoven fibers with interconnected _

continuous free space between the fibers

nonwoven electrospun materials are a soldering like attachment of the _

nanofibers at their junction points through interpenetration and entanglement of polymer chains after annealing

what are the characteristics of electrospun nano fibers

good molecular alignment relatively low degree of crystallinity relatively poor mechanical properties in the case of pla glass transition temperature is smaller than bulk pla

what is cellular signaling

living cells of organism communicate direct contact between cells or chemical signals carrier by neurotransmitter substances hormones cyclic amp

what is cell communication

communication among cells to coordinate their behavior to benefit organism as a whole

what are the cell signaling systems elucidated in animal cells

cell surface and intracellular receptor proteins protein kinases protein phosphates gtp binding proteins

functions of biological membranes

enclosure for cells exchange of material sites of biological reactions facilitate cell motion enable recognition cell fusion

What is the intrinsic barrier of GI tract

epithelial cells lining digestive tube and tight junctions that tie them down

what is extrinsic barrier of GI tract

secretions and other influences that are not physically part of the epithelium but affect epithelial cells and maintain their barrier function

what are the export transporters through the GI barrier

atp dependent p glycoprotein mdrp1 mdrp2

what are the uptake transporters through GI barrier

sodium dependent bile transporter peptide transporters glucose transporter organic anion transporter

The rate and extent of drug absorption from the small intestine depends on

release of the active ingredient from a dosage form solubility in its liquid phase of gi contents transport of the dissolved compound or the intact dosage from the stomach into duodenum

Stimuli responsive polymers undergo relatively large and abrupt _

physical chemical changes in response to small external changes in environment

What are the steps of nanoparticle drug delivery and targeting using receptor mediated endocytosis

internalization early endosomes acidified endosomes endosomal release recycling endosomes membrane fusion

what is paclitaxel and how does it function

microtubule stabilizing agent promotes polymerization of tubulin causes cell death by disrupting dynamics for cell division

what is doxorubicin and how does it function

inhibiting synthesis of nucleic acids within cancer cells