Future cell-based therapies such as tissue engineering will benefit from a source of autologous pluripotent stem cells. For mesodermal tissue engineering, one such source of cells is the bone marrow stroma. The bone marrow compartment contains several cell populations, including mesenchymal stem cells (MSCs) that are capable of differentiating into adipogenic, osteogenic, chondrogenic, and myogenic cells. However, autologous bone marrow procurement has potential limitations. An alternate source of autologous adult stem cells that is obtainable in large quantities, under local anesthesia, with minimal discomfort would be advantageous. In this study, we determined if a population of stem cells could be isolated from human adipose tissue. Human adipose tissue, obtained by suction-assisted lipectomy (i.e., liposuction), was processed to obtain a fibroblast-like population of cells or a processed lipoaspirate (PLA). These PLA cells can be maintained in vitro for extended periods with stable population doubling and low levels of senescence. Immunofluorescence and flow cytometry show that the majority of PLA cells are of mesodermal or mesenchymal origin with low levels of contaminating pericytes, endothelial cells, and smooth muscle cells. Finally, PLA cells differentiate in vitro into adipogenic, chondrogenic, myogenic, and osteogenic cells in the presence of lineage-specific induction factors. In conclusion, the data support the hypothesis that a human lipoaspirate contains multipotent cells and may represent an alternative stem cell source to bone marrow-derived MSCs.

/pdf/multilineage-cells-from-human-adipose-tissue-implications-4z32vwpf0q.pdf

Multilineage cells from human adipose tissue: implications for cell-based therapies.

On the mechanisms of biocompatibility.

Fibroblasts can condense a hydrated collagen lattice to a tissue-like structure 1/28th the area of the starting gel in 24 hr. The rate of the process can be regulated by varying the protein content of the lattice, the cell number, or the con- centration of an inhibitor such as Colcemid. Fibroblasts of high population doubling level propagated in vitro, which have left the cell cycle, can carry out the contraction at least as efficiently as cycling cells. The potential uses of the system as an immu- nologically tolerated "tissue" for wound hea ing and as a model for studying fibroblast function are discussed.

Production of a tissue-like structure by contraction of collagen lattices by human fibroblasts of different proliferative

The intervertebral disc is a cartilaginous structure that resembles articular cartilage in its biochemistry, but morphologically it is clearly different. It shows degenerative and ageing changes earlier than does any other connective tissue in the body. It is believed to be important clinically because there is an association of disc degeneration with back pain. Current treatments are predominantly conservative or, less commonly, surgical; in many cases there is no clear diagnosis and therapy is considered inadequate. New developments, such as genetic and biological approaches, may allow better diagnosis and treatments in the future.

/pdf/degeneration-of-the-intervertebral-disc-297lygwdik.pdf

Degeneration of the intervertebral disc

http://orion.bme.columbia.edu/lulab/pdf/Altman-silk-ACL-MSC-2002.pdf

Silk matrix for tissue engineered anterior cruciate ligaments

We evaluated 41 knees 24 to 48 months after anterior cruciate ligament reconstruction was performed using multiple autogenous semitendinosus tendons. The ipsilateral free semitendinosus tendon was tripled or quadrupled to make a graft 7 to 10 mm in diameter and more than 60 mm long. When the diameter of the graft was less than 7 mm, an ipsilateral doubled gracilis tendon was also used (in seven cases). Twenty-three patients (56%) returned to their preinjury activity levels. According to the patients' subjective assessment, 34 (83%) graded themselves as normal or nearly normal. No patient reported giving way of the knee or limitation of knee motion. The average anterior laxity difference between the involved knee and contralateral uninjured knee was 1.5 mm at 200 N. Twenty-nine patients (71%) demonstrated an anterior laxity difference of 3 mm or less when the involved knee was compared with the contralateral uninjured knee. Quadriceps muscle strength was 90% compared with the contralateral healthy limb, and hamstring muscle strength was equivalent to the contralateral limb. In our study, tripled or quadrupled semitendinosus free tendons were excellent anterior cruciate ligament grafts for restoring knee stability, recovering thigh muscle power, and preserving knee motion.

Anterior cruciate ligament reconstruction with multistranded autogenous semitendinosus tendon

To investigate intraarticular lesions producing persist ent postoperative pain, we arthroscopically examined 31 ankles in 31 patients (15 women and 16 men) with lateral ligament injury. The patients ranged in age from 15 to 33 years, with a mean of 20 years. Nine patients were freshly injured, and 22 patients had chronic inju ries. All of the patients underwent arthroscopic exami nation immediately before the ligament operation. Chondral lesions were found in 89% of the freshly injured ankles and 95% of the ankles with chronic injuries. Most of these lesions were in the medial half of the ankle joint, especially in the anteromedial edge of the tibial plafond. After followup for 1 year postop eratively, persistent pain was noted in 4 patients who had chondral lesions of greater than one-half the thick ness of the articular cartilage. Pain and tenderness were localized at the anteromedial joint line, corre sponding to the location of the chondral lesions. Chon dral lesions of greater than one-half the thick...

Articular cartilage lesions in ankles with lateral ligament injury An arthroscopic study

Cartilage repair using an in vitro generated scaffold-free tissue-engineered construct derived from porcine synovial mesenchymal stem cells

Purpose The purpose of this study was to histologically identify the direct and indirect insertion of the femoral anterior cruciate ligament (ACL) insertion. Furthermore, we quantitatively measured the direct femoral insertion area by use of the 3-dimensional (3D) volume-rendered (VR) computed tomography (CT) model. Methods By use of 8 intact cadaveric knees, the lateral femoral condyle including the ACL attachment was sectioned for histologic examination in 3 oblique-axial planes parallel to the roof of the intercondylar notch and in the sagittal planes. Before sectioning, these knees had been subjected to CT to obtain 3D VR images of the femur. Once the direct insertion of the ACL was identified on each histologic section, the corresponding image was superimposed on the corresponding CT image. Results The direct ACL insertion, in which dense collagen fibers were connected to the bone by the fibrocartilaginous layer, was microscopically identified at the region between the posteromedial articular cartilage margin of the lateral femoral condyle and the linear bony ridge 7 to 10 mm anterior to the articular cartilage margin. Meticulous comparison of histologic analysis and the 3D VR CT model showed that the ACL direct insertion coincided with a crescent-shaped hollow just behind the linear bony ridge. The direct insertion measured 17.4 ± 0.9 mm (mean ± SD) in length, 8.0 ± 0.5 mm in width, and 128.3 ± 10.5 mm 2 in area. Conclusions The direct insertion of the ACL is located in the depression between the resident's ridge and the articular cartilage margin on the lateral femoral condyle. It measured 17.4 ± 0.9 mm in length, 8.0 ± 0.5 mm in width, and 128.3 ± 10.5 mm 2 in area. Clinical Relevance Delineation of the ACL femoral direct insertion by 3D VR CT could be a useful tool for planning of accurate femoral tunnel positioning in anatomic ACL reconstruction.

Direct Anterior Cruciate Ligament Insertion to the Femur Assessed by Histology and 3-Dimensional Volume-Rendered Computed Tomography

Type IX collagen, containing molecules of the three distinct polypeptides alpha 1(IX), alpha 2(IX), and alpha 3(IX), is an interesting hybrid extracellular matrix component in cartilage and eye tissues, with the properties of both a proteoglycan and a collagen. The alpha 1 (IX) chain has two forms, as a result of the tissue-specific utilization of two alternative promoters; the alpha 2(IX) chain carries a covalently attached glycosaminoglycan side chain. We have introduced a gene construct controlled by a tissue-specific promoter/enhancer and expressing a truncated alpha 1(IX) chain into mice. Examination of the offspring of two different founders revealed pathological changes similar to osteoarthritis in the articular cartilage of knee joints. In addition, mice homozygous for the transgene developed mild chondrodysplasia (i.e., mild dwarfism, anterior tonguing in the vertebral bodies, and ophthalmopathy). The relative ratio of transgene product to the endogenous alpha 1(IX) chain was approximately one in homozygotes and less than one in heterozygotes. Therefore, the phenotypic severity correlated well with the level of transgene expression. These findings suggest that mutations in type IX collagen genes may cause certain forms of osteoarthritis and chondrodysplasia in humans.

https://www.pnas.org/content/pnas/90/7/2870.full.pdf

Ken Nakata

Papers

Anterior cruciate ligament reconstruction with multistranded autogenous semitendinosus tendon

Articular cartilage lesions in ankles with lateral ligament injury An arthroscopic study

Cartilage repair using an in vitro generated scaffold-free tissue-engineered construct derived from porcine synovial mesenchymal stem cells

Direct Anterior Cruciate Ligament Insertion to the Femur Assessed by Histology and 3-Dimensional Volume-Rendered Computed Tomography

Osteoarthritis associated with mild chondrodysplasia in transgenic mice expressing alpha 1(IX) collagen chains with a central deletion