Delivery Of TGF-β1 Research Articles

In situ chondrogenic differentiation of human adipose tissue-derived stem cells in a TGF-β1 loaded fibrin–poly(lactide-caprolactone) nanoparticulate complex

When conducting cartilage tissue engineering with stem cells, it is well known that chemical and physical stimulations are very important for the induction and maintenance of chondrogenesis. In this study, we induced chondrogenic differentiation of human adipose tissue-derived stem cells (hASCs) in situ by effective stimulation via the continuous controlled release of TGF-β1 from a heparin-functionalized nanoparticle–fibrin–poly(lactide-co-caprolactone) (PLCL) complex. PLCL scaffolds were fabricated with 85% porosity and 300–500μm pore size by a gel-pressing method. Heparin-functionalized nanoparticles were prepared by a solvent-diffusion method, composed of poly(lactide-co-glycolide) (PLGA), Pluronic F-127, and heparin, and then TGF-β1 was loaded to the nanoparticles. A mixture of hASCs, fibrin gels and TGF-β1 loaded nanoparticles was then seeded onto PLCL scaffolds and cultured in vitro, after which they were subcutaneously implanted into nude mice for up to five weeks. The results of in vitro and in vivo studies revealed that chondrogenic differentiation of the hASCs on the complex was induced and sustained by continuous stimulation by TGF-β1 from the heparin-functionalized nanoparticles. In addition, there was no significant difference between the predifferentiation condition prior to incubation in chondrogenic medium and the proliferation condition, which suggests that in situ chondrogenic differentiation of hASCs was induced by the TGF-β1 loaded nanoparticles. Consequently, the hybridization of fibrin and PLCL scaffolds for three-dimensional spatial organization of cells and the effective delivery of TGF-β1 using heparin-functionalized nanoparticles can induce hASCs to differentiate to a chondrogenic lineage and maintain their phenotypes.

191. Examining the Role of Elevated Blood Glucose in the Severity of Arthrofibrosis Using Intra-Articular Gene Delivery of TGF-β1

191. Examining the Role of Elevated Blood Glucose in the Severity of Arthrofibrosis Using Intra-Articular Gene Delivery of TGF-β1

Intranasal delivery of transforming growth factor-beta1 in mice after stroke reduces infarct volume and increases neurogenesis in the subventricular zone

BackgroundThe effect of neurotrophic factors in enhancing stroke-induced neurogenesis in the adult subventricular zone (SVZ) is limited by their poor blood-brain barrier (BBB) permeability.Intranasal administration is a noninvasive and valid method for delivery of neuropeptides into the brain, to bypass the BBB. We investigated the effect of treatment with intranasal transforming growth factor-β1 (TGF-β1) on neurogenesis in the adult mouse SVZ following focal ischemia. The modified Neurological Severity Scores (NSS) test was used to evaluate neurological function, and infarct volumes were determined from hematoxylin-stained sections. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) labeling was performed at 7 days after middle cerebral artery occlusion (MCAO). Immunohistochemistry was used to detect bromodeoxyuridine (BrdU) and neuron- or glia-specific markers for identifying neurogenesis in the SVZ at 7, 14, 21, 28 days after MCAO.ResultsIntranasal treatment of TGF-β1 shows significant improvement in neurological function and reduction of infarct volume compared with control animals. TGF-β1 treated mice had significantly less TUNEL-positive cells in the ipsilateral striatum than that in control groups. The number of BrdU-incorporated cells in the SVZ and striatum was significantly increased in the TGF-β1 treated group compared with control animals at each time point. In addition, numbers of BrdU- labeled cells coexpressed with the migrating neuroblast marker doublecortin (DCX) and the mature neuronal marker neuronal nuclei (NeuN) were significantly increased after intranasal delivery of TGF-β1, while only a few BrdU labeled cells co-stained with glial fibrillary acidic protein (GFAP).ConclusionIntranasal administration of TGF-β1 reduces infarct volume, improves functional recovery and enhances neurogenesis in mice after stroke. Intranasal TGF-β1 may have therapeutic potential for cerebrovascular disorders.

Cellular delivery of TGFβ1 promotes osteoinductive signalling for bone regeneration

Administration of osteoinductive growth factors to wound sites, alone or in conjunction with a delivery vehicle, is an appealing treatment option for critical bone defects. The delivery of cells transfected with genes encoding for osteoinductive growth factors, such as TGFbeta(1), represents an attractive option to locally deliver constant levels of these growth factors to stimulate new bone formation at the defect site. Using non-viral transfection methods, we showed that osteoblasts can be genetically modified in vitro to secrete sustained therapeutic levels of TGFbeta(1) in its active form through control of the transfected cell environment. In addition, delivery of TGFbeta(1) produced by genetically modified cells that contained the proper post-translational modifications provided a more robust cellular response compared to administration of bacterially-derived recombinant TGFbeta(1). Migration and subsequent proliferation of osteoblasts are critical aspects of the initial steps in the cascade of new bone tissue formation. Exposure to mammalian-derived TGFbeta(1) induced a more pronounced chemotactic response upon administration of 10 pg/ml TGFbeta(1), whereas osteoblasts showed enhanced levels of metabolic activity at 100 pg/ml, which is indicative of greater levels of cellular proliferation when compared to addition of the same levels of recombinant TGFbeta(1). This increased efficacy of cell-derived TGFbeta(1) over recombinant forms of TGFbeta(1), combined with provision of a continual source of TGFbeta(1), highlights the advantages of delivering genetically modified cells over exogenous protein delivery for bone tissue engineering.

Stability, characterization, formulation, and delivery system development for transforming growth factor-beta 1.

This chapter has reviewed the multifunctional role that the TGF-β play with diverse proliferative and suppressive effects on many different cell types. The various in vitro and in vivo effects of TGF-β was discussed with emphasis on the therapeutic potential of this growth factor in areas such as wound healing and bone regeneration. The structure and properties of TGF-β were presented, followed by a more detailed description of the characterization and stabilization of TGF-β1) in both the liquid and lyophilized state. The chapter concluded with a review of some of the different controlled release systems that have been utilized for the delivery of TGF-β1 to various preclinical models. Clearly the therapeutic potential for TGF-β1) is great. Both the formulation and delivery of this growth factor will play an important role in its eventual clinical success

Regulation of experimental mucosal inflammation

Studies conducted over the past 10 years have provided ample evidence that many types of inflammations arising from basic abnormalities of immune regulation are ultimately ‘funneled’ through a Th1 or Th2 T cell-mediated immune reaction. Thus, by understanding these types of reactions and, in particular, by identifying their natural checkpoints, one can control the inflammation regardless of its more basic causes. A case in point is the inflammatory disease of the intestine known as Crohn disease, a disease now thought to be due to one or more abnormalities leading to an excessive immune response to elements of the bacterial microflora of the gut. Both in murine models and by study of Crohn disease itself, we have shown that Crohn inflammation is due to a Th1 T-cell abnormality involving overproduction of interleukin (IL)-12, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. In addition, we and others have shown that treatment of mice with anti-IL-12 or other agents that downregulate the level of IL-12 secretion can have a dramatic effect on the inflammation. This is because anti-IL-12 administration leads to apoptosis of activated Th1 T cells. A second checkpoint of Th1 T-cell-mediated inflammation involves its downregulation by the suppressor cytokine, transforming growth factor (TGF)-β. We have been delivering TGF-β to mice with experimental intestinal inflammation, using several novel approaches. In particular, we have successfully treated such mice with intranasally administered DNA encoding active TGF-β. Another approach currently under investigation is delivery of TGF-β by gene therapy. These and other developments in the understanding of inflammation paint a bright future for cytokine-based therapeutic agents. It is now apparent that these therapies are not only effective and safe but also potentially longlasting.

Effect of local injection of activin A on bone formation in newborn rats

In order to examine the effect of activin A on the process of bone formation, activin A was injected onto the periosteum of parietal bone in newborn rats, and the effect was compared with that of transforming growth factor (TGF)-β. The daily periosteal injection of activin A increased the thickness of both the periosteal and bone matrix layers in a dose- and time-dependent manner. A maximal effect was obtained with 5.0 μg/day activin A. The time course of the effect of activin A on the periosteal thickness was similar to that of TGF-β1. However, the effect of TGF-β1 was much more pronounced and was mainly on fibroblasts and inflammatory cells. The time course of the effect of activin A on the thickness of bone matrix layer was different from that of TGF-β1. The effect of TGF-β1 reached maximum (1.8-fold) within 3 days, whereas that of activin A did not develop until day 6 and reached maximum at the end of the 12-day injection period (1.4-fold). Histological examinations revealed that both TGF-β1 and activin A increased the number of alkaline phosphatase-positive osteoblastic cells. These results demonstrate that periosteal injection of activin A stimulates bone formation. In addition, although the possibility cannot be ruled out that the dramatic effect of TGF-β1 on the periosteal layer might have affected the delivery of TGF-β1 to the bone surface, these observations also suggest that the mode of action of activin A may be different from that of TGF-β1. Because bone matrix contains abundant activin A, such an effect of activin A may have a significant role in the regulation of bone formation.