Biomaterial Database

Structure of pericellular matrix around agarose-embedded chondrocytes. 2007

M A Dimicco, and J D Kisiday, and H Gong, and A J Grodzinsky

Center for Biomedical Engineering and Biological Engineering Division, Massachusetts Institute of Technology, Cambridge, MA, USA. michael.dimarco@genzyme.com

OBJECTIVE Determine whether the structure of the type VI collagen component of the chondrocyte pericellular matrix (PCM) generated by agarose-embedded chondrocytes in culture is similar to that found in native articular cartilage. METHODS Confocal microscopy, quick-freeze deep-etch electron microscopy, and real-time polymerase chain reaction (PCR) were used to investigate temporal and spatial patterns of type VI collagen protein deposition and gene expression by bovine chondrocytes during 4 weeks of culture within a 2% agarose hydrogel. Similar analyses were performed on chondrocytes within samples of intact cartilage obtained from the same joint surfaces as those used for cell isolation for comparison. RESULTS Type VI collagen accumulated uniformly around cells embedded in agarose, with the rate of deposition slowing after the second week. After 1 week, PCM fibrils were observed to be oriented perpendicular to the cell surface, in contrast with the primarily tangential fibrillar arrangement observed in native articular cartilage. Expression of col6 in agarose-embedded cells was initially much higher ( approximately 400%) than that in chondrocytes within cartilage. Expression of col6 in the cultured chondrocytes declined by approximately 60% after 1 week, and remained stable thereafter. CONCLUSIONS PCM structure and composition around cells in a hydrogel scaffold may be different than that in native cartilage, with potential implications for mass transport, mechanotransduction, and ultimately, the success of tissue engineering approaches.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D002358	Cartilage, Articular	A protective layer of firm, flexible cartilage over the articulating ends of bones. It provides a smooth surface for joint movement, protecting the ends of long bones from wear at points of contact.	Articular Cartilage,Articular Cartilages,Cartilages, Articular
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D005109	Extracellular Matrix	A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere.	Matrix, Extracellular,Extracellular Matrices,Matrices, Extracellular
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012685	Sepharose		Agarose,Sepharose 4B,Sepharose C1 4B,4B, Sepharose C1,C1 4B, Sepharose
D016133	Polymerase Chain Reaction	In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.	Anchored PCR,Inverse PCR,Nested PCR,PCR,Anchored Polymerase Chain Reaction,Inverse Polymerase Chain Reaction,Nested Polymerase Chain Reaction,PCR, Anchored,PCR, Inverse,PCR, Nested,Polymerase Chain Reactions,Reaction, Polymerase Chain,Reactions, Polymerase Chain
D019902	Chondrocytes	Polymorphic cells that form cartilage.	Chondroblasts,Chondroblast,Chondrocyte
D020219	Chondrogenesis	The formation of cartilage. This process is directed by CHONDROCYTES which continually divide and lay down matrix during development. It is sometimes a precursor to OSTEOGENESIS.