Hyoepiglottic ligament collagen and elastin fiber composition and changes associated with aging.

Objective: The epiglottis may contribute to upper airway obstruction in approximately 10% of patients with obstructive sleep apnea. Clinical experience indicates that older patients may be more likely to have epiglottis-related obstruction. This study was designed to examine tissue characteristics of the hyoepiglottic ligament as a possible factor in epiglottis-related obstruction based on previous research suggesting that older adults have fewer collagen, elastin, and muscle fibers in the hyoepiglottic ligament.

Acidosis and Formaldehyde Secretion as a Possible Pathway of Cancer Pain and Options for Improved Cancer Pain Control.

The prevalence of cancer pain in patients with cancer is high. The majority of efforts are spent on research in cancer treatment, but only a small fraction focuses on cancer pain. Pain in cancer patients, viewed predominantly as a secondary issue, is considered to be due to the destruction of tissues, compression of the nerves, inflammation, and secretion of biological mediators from the necrotic tumor mass.

Zinc as a possible preventive and therapeutic agent in pancreatic, prostate, and breast cancer.

Zinc is a vital nutrient for human health. Over 300 biological functions in the human body rely on zinc. Even though zinc is incredibly important for our physiology and pathology, our current understanding of zinc, as it relates to tumor cell biology, leaves much to be desired.

The synergetic effect of hydrogel stiffness and growth factor on osteogenic differentiation.

Cells respond to various chemical signals as well as environmental aspects of the extracellular matrix (ECM) that may alter cellular structures and functions. Hence, better understanding of the mechanical stimuli of the matrix is essential for creating an adjuvant material that mimics the physiological environment to support cell growth and differentiation, and control the release of the growth factor. In this study, we utilized the property of transglutaminase cross-linked gelatin (TG-Gel), where modification of the mechanical properties of TG-Gel can be easily achieved by tuning the concentration of gelatin.

Injectable gel graft for bone defect repair.

Aim: To examine the performance of an injectable gel graft made of transglutaminase (Tg)-crosslinked gelatin gel with BMP-2 (BMP-2-Tg-Gel) for bone defect repair in animal models.

Materials & Methods: BMP-2 mixed with gelatin gel was crosslinked using Tg. The release of tethered BMP-2 through autocrine and paracrine pathways was demonstrated by using C2C12 and NIH 3T3 cells, respectively.

The effects of heparin binding proteins in platelet releasate on bone formation.

Platelet releasates (PR) from platelet-rich plasma (PRP) preparations are often used as an adjuvant for tissue repair. However, many in vitro and in vivo published studies have shown inconsistent results since outcomes depended on the methods of PRP preparation, the dosage of PRP and wound repair models used. Among the 300 proteins released by platelets, a number of them have the ability to bind to heparin, a sulfated glycosaminoglycan well known for its anticoagulant activity.

Delivery of demineralized bone matrix powder using a thermogelling chitosan carrier.

Demineralized bone matrix (DBM) powder is widely used for bone regeneration due to its osteoinductivity and osteoconductivity. However, difficulties with handling, its tendency to migrate from graft sites, and lack of stability after surgery can sometimes limit the clinical utility of this material. In this work, the possibility of using a thermogelling chitosan carrier to deliver DBM powder was assessed.

Cell delivery using an injectable and adhesive transglutaminase-gelatin gel.

In this study, we developed an injectable gelatin-transglutaminase (TGase) gel for cell delivery. The procedure provides a minimally invasive approach to deliver cells into tissue in a manner that improves localization. The results indicate gelatin-TGase to be noncytotoxic and to have adhesive properties that help localize and prevent the scattering of the cells after delivery.

The effect of thrombin activation of platelet-rich plasma on demineralized bone matrix osteoinductivity.

Background: Demineralized bone matrix is an osteoinductive and osteoconductive material that is often used in orthopaedic surgery to induce bone formation. Autologous platelet-rich plasma, which contains proliferative and chemoattractant growth factors, has been used as a demineralized bone matrix adjuvant with mixed results. One variable during clinical use appears to be whether the platelet-rich plasma is activated with thrombin or is implanted in a liquid form with intact platelets.

Intra-articular injection of collagenase induced experimental osteoarthritis of the lumbar facet joint in rats.

We aimed to establish an animal model to investigate primary osteoarthritis of the lumbar facet joints after collagenase injection in rats and its effects on chondrocyte apoptosis. We hypothesized that osteoarthritic-like changes would be induced by collagenase injection and that apoptosis of chondrocytes would increase. Collagenase (1, 10, or 50 U) or saline (control) was injected into the lumbar facet joints.

Are we getting enough sulfur in our diet?

Sulfur, after calcium and phosphorus, is the most abundant mineral element found in our body. It is available to us in our diets, derived almost exclusively from proteins, and yet only 2 of the 20 amino acids normally present in proteins contains sulfur. One of these amino acids, methionine, cannot be synthesized by our bodies and therefore has to be supplied by the diet.

Effects of gamma irradiation on osteoinduction associated with demineralized bone matrix.

Gamma irradiation is frequently used to sterilize implanted devices but has limitations when used on biologically active materials and composites. In this study, we have evaluated the changes of biological activity of demineralized bone matrix (DBM) in the dry state and in the presence of aqueous and non-aqueous carriers while exposed to various levels of ionizing radiation. The activity of DBM in the dry state remains relatively stable with only a small loss of activity.

Transdermal delivery of amino acids and antioxidants enhance collagen synthesis: in vivo and in vitro studies.

One of the most visible changes associated with the aging process in humans relates to a progressive thinning of the skin. This results from a decline in both collagen and glycosaminoglycans, as well as from changes in their chemical structure and 3-dimentional organization. Transdermal administration of antioxidants, a -lipoic acid (LA) (0.

Chitosan/gelatin-based films crosslinked by proanthocyanidin.

Novel polymer networks consisting of crosslinked gelatin/chitosan were prepared by a solution casting technique. Methods for bulk crosslinking were developed to modify the gelatin/chitosan blends with the use of a nontoxic crosslinking reagent, proanthocyanidin (PA). FTIR spectral analyses of the preparations showed network formations of crosslinked gelatin, chitosan, and PA by amide and ester linkages.

Effects of moisture and temperature on the osteoinductivity of demineralized bone matrix.

Demineralized bone matrix (DBM) is a well established osteoinductive bone graft material. It has been mixed with a variety of carriers to adjust to different forms of handling for a variety of applications. The impact of the various carriers on osteoinductivity remains largely unknown.

Combined effects of phosphatidylcholine and demineralized bone matrix on bone induction.

The osteoinductivity of demineralized bone matrix (DBM) becomes significantly reduced if the specimens are further delipidated with chloroform-methanol. The addition of phosphatidylcholine (PC), a major constituent of the lipid fraction present in the calcification front during normal bone formation, can restore the biological activity. Active endochondral bone formation is observed in the DBM/PC implants placed in the anterior abdominal wall musculature or subcutaneously for 28 days.

Quantitative and sensitive in vitro assay for osteoinductive activity of demineralized bone matrix.

A sensitive, rapid, reliable and quantitative method to check the bone forming potential of demineralized bone matrix (DBM) has been developed. The osteoinductivity of the bone morphogenetic proteins (BMPs), present in DBM, can be measured in vitro using a pluripotent myoblast C2C12 cell line. Alkaline phosphatase activity induced by co-incubation of DBM with C2C12 cells was dose-responsive and corresponds to the amount of active BMPs in DBM.

Proanthocyanidin: a natural crosslinking reagent for stabilizing collagen matrices.

While attempting to find a suitable crosslinking reagent for biopolymers, a naturally occurring proanthocyanidin (PA) obtained from grape seeds was selected to fix biological tissues. The cytotoxicity and crosslinking rate, reflected by the in vitro and in vivo degradation of fixed matrices has been studied. The shrinkage temperature of the fixed bovine pericardium increased from 66 to 86 degrees C.

Collagen-targeted BMP3 fusion proteins arrayed on collagen matrices or porous ceramics impregnated with Type I collagen enhance osteogenesis in a rat cranial defect model.

Bone morphogenetic protein 3 (BMP3) is a potent osteoinductive growth factor belonging to the TGF-beta superfamily. In this study, we engineered a recombinant BMP3 protein to include an auxiliary collagen-targeting domain derived from von Willebrand coagulation factor (vWF). The collagen-targeted BMP3 fusion protein (rhBMP3-C) was expressed in E.