Every tissue and organ has its own 3-dimensional (3D) extracellular matrix (ECM) organization. Cells in a 3D bioscaffold for tissue engineering typically align new ECM components according to the bioscaffold provided. Therefore, scaffolds with a specific 3D structural design resembling the actual ECM of a particular tissue may have great potential in tissue engineering. Here, we show that, using specific freezing regimes, 3D scaffolds that mimic the 3D architecture of specific tissues can be made from collagen. Three examples are given, namely, scaffolds resembling the cup-shaped parenchymal (alveolar) architecture of lung, scaffolds that mimic the parallel collagen organization of tendon, and scaffolds that mimic the 3D organization of skin. For the preparation of these tissue-specific scaffolds, we relied on simple techniques without the need for expensive or customized equipment. Freezing rate, type of suspension medium, and additives (e.g., ethanol) were found to be prime parameters in controlling scaffold morphology.

Systemic chemotherapy is a primary strategy in the treatment of cancer, but comes with a number of limitations such as toxicity and unfavorable biodistribution. To overcome these issues, numerous targeting systems for specific delivery of chemotherapeutics to tumor cells have been designed and evaluated. Such strategies generally address subsets of tumor cells, still allowing the progressive growth of tumor cells not expressing the target. Moreover, tumor stem cells and tumor supportive cells, such as cancer associated fibroblasts and cancer associated macrophages, are left unaffected by this approach. In this review, we discuss an alternative targeting strategy aimed at delivery of anti-tumor drugs to the tumoral extracellular matrix with the potential to eliminate all cell types. The extracellular matrix of tumors is vastly different from that of healthy tissue and offers hooks for targeted drug delivery. It is concluded that matrix targeting is promising, but that clinical studies are required to evaluate translation.