Massachusetts Institute of Technology

About: Massachusetts Institute of Technology is a education organization based out in Cambridge, Massachusetts, United States. It is known for research contribution in the topics: Population & Laser. The organization has 116795 authors who have published 268000 publications receiving 18272025 citations. The organization is also known as: MIT & M.I.T..

Regulation of transport pathways in tumor vessels: Role of tumor type and microenvironment

Abstract: Novel anti-neoplastic agents such as gene targeting vectors and encapsulated carriers are quite large (approximately 100–300 nm in diameter) An understanding of the functional size and physiological regulation of transvascular pathways is necessary to optimize delivery of these agents Here we analyze the functional limits of transvascular transport and its modulation by the microenvironment One human and five murine tumors including mammary and colorectal carcinomas, hepatoma, glioma, and sarcoma were implanted in the dorsal skin-fold chamber or cranial window, and the pore cutoff size, a functional measure of transvascular gap size, was determined The microenvironment was modulated: (i) spatially, by growing tumors in subcutaneous or cranial locations and (ii) temporally, by inducing vascular regression in hormone-dependent tumors Tumors grown subcutaneously exhibited a characteristic pore cutoff size ranging from 200 nm to 12 μm This pore cutoff size was reduced in tumors grown in the cranium or in regressing tumors after hormone withdrawal Vessels induced in basic fibroblast growth factor-containing gels had a pore cutoff size of 200 nm Albumin permeability was independent of pore cutoff size These results have three major implications for the delivery of therapeutic agents: (i) delivery may be less efficient in cranial tumors than in subcutaneous tumors, (ii) delivery may be reduced during tumor regression induced by hormonal ablation, and (iii) permeability to a molecule is independent of pore cutoff size as long as the diameter of the molecule is much less than the pore diameter

Hydrogels in regenerative medicine

Abstract: Hydrogels, due to their unique biocompatibility, flexible methods of synthesis, range of constituents, and desirable physical characteristics, have been the material of choice for many applications in regenerative medicine. They can serve as scaffolds that provide structural integrity to tissue constructs, control drug and protein delivery to tissues and cultures, and serve as adhesives or barriers between tissue and material surfaces. In this work, the properties of hydrogels that are important for tissue engineering applications and the inherent material design constraints and challenges are discussed. Recent research involving several different hydrogels polymerized from a variety of synthetic and natural monomers using typical and novel synthetic methods are highlighted. Finally, special attention is given to the microfabrication techniques that are currently resulting in important advances in the field.

Information Technology, Workplace Organization, and the Demand for Skilled Labor: Firm-Level Evidence

Abstract: We investigate the hypothesis that the combination of three related innovations—1) information technology (IT), 2) complementary workplace reorganization, and 3) new products and services—constitute a significant skill-biased technical change affecting labor demand in the United States. Using detailed firm-level data, we find evidence of complementarities among all three of these innovations in factor demand and productivity regressions. In addition, firms that adopt these innovations tend to use more skilled labor. The effects of IT on labor demand are greater when IT is combined with the particular organizational investments we identify, highlighting the importance of IT-enabled organizational change.