细胞外矩阵以组织特定的方式限制纳米粒子扩散和细胞吸收.

Overview
In order to maintain tissue organization, many animal cells are surrounded by structural molecules that make up the extracellular matrix (ECM). Together, the molecules in the ECM maintain the structural integrity of tissue as well as the remarkable specific properties of certain tissues.
Composition of the Extracellular Matrix
The extracellular matrix (ECM) is commonly composed of ground substance, a gel-like fluid, fibrous components, and many structurally and functionally diverse...

Overview

Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...

Drugs must traverse multiple biological barriers, such as multi-layered skin, single-layered intestinal epithelium, and the plasma membrane, to reach their target sites within the body. The plasma membrane, a highly structured composite of phospholipids, carbohydrates, and proteins, is the cell's protective boundary, facilitating selective substance exchange.
Phospholipids arrange themselves into a bilayer, with hydrophilic heads oriented outward and hydrophobic tails facing inward.

Unlike epithelial tissue, which is composed of cells closely packed with little or no extracellular space in between, connective tissue cells are dispersed in a matrix. This extracellular matrix (ECM) is composed of fibrous proteins like collagen, elastin, and fibronectin in a ground substance consisting of interstitial fluid, cell adhesion proteins, and proteoglycans. The proteoglycans form a gel-like material in the spaces between cells and provide hydration, buffering, binding, and force...

Upon entering the systemic circulation, drugs can distribute into the interstitial and intracellular fluid of various tissue cells. This distribution is facilitated by the binding of drugs to different cellular components within tissues, which may lead to drug accumulation in specific areas. Drugs bound to tissue components serve as reservoirs that release free drugs back into the system, prolonging the drug's overall action. However, this accumulation can also result in local toxicity.
For...