Methods for modulating chondrocyte proliferation using pulsing electromagnetic fields

Abstract

Compositions and methods are provided for modulating the growth, development and repair of bone, cartilage or other connective tissue. Devices and stimulus waveforms are provided to differentially modulate the behavior of osteoblasts, chondrocytes and other connective tissue cells to promote proliferation, differentiation, matrix formation or mineralization for in vitro or in vivo applications. Continuous-mode and pulse-burst-mode stimulation of cells with charge-balanced signals may be used. Bone, cartilage and other connective tissue growth is stimulated in part by nitric oxide release through electrical stimulation and may be modulated through co-administration of NO donors and NO synthase inhibitors. Bone, cartilage and other connective tissue growth is stimulated in part by release of BMP-2 and BMP-7 in response to electrical stimulation to promote differentiation of cells. The methods and devices described are useful in promoting repair of bone fractures, cartilage and connective tissue repair as well as for engineering tissue for transplantation.

Description

[0001] Cross application of related applications

[0002] This application claims U.S. Provisional Patent Application 60 / 687,430, filed June 3, 2005, U.S. Provisional Patent Application 60 / 693,490, filed June 23, 2005, U.S. Provisional Patent Application 60 / 782,462, filed March 15, 2006 and priority of US Provisional Patent Application 60 / 790,128, filed April 7, 2006. Background technique

[0003] Diseases and injuries associated with bone and cartilage have a large impact on the human population. Approximately 5 million fractures occur each year in the United States alone. About 10% of these have delayed union, and of these, 150,000 to 200,000 nonunion fractures occur with loss of productivity and independence. In the case of cartilage, severe chronic forms of knee cartilage damage can lead to greater deterioration of the articular cartilage and may eventually lead to replacement of the entire knee joint. Each year, approximately 200,000 total knee replacement surgeries ar...

Examples

Embodiment 1

[0141] Effects of PEMF signaling structure on mineralization and morphology in primary osteoblast cultures

[0142] The goal of this study was to compare two PEMF waveform structures delivered by capacitive coupling by evaluating biochemical and morphological changes in primary osteocyte cultures.

[0143] method

[0144] Osteoblast culture: primary human osteoblasts (CAMBREX , Walkersville, MD) was amplified to 75% confluence (confluence), and seeded directly on the previously described LAB-TEK at a density of 50,000 cells / ml TM (NALGENUNC INTERNATIONAL TM, Rochester, NY) room. Cultures were initially supported on basal osteoblast medium in the absence of differentiation factors. When the cultures reached 70% confluency in house, the medium was supplemented with hydrocortisone-21-hemisuccinate (200 mM final concentration), β-glycerophosphate (10 mM final concentration) and ascorbic acid. At 37°C, 5% CO 2 , Osteoblasts were cultured in humid air under 95% air for 21 day...

Embodiment 2

[0160] Use of niobium "salt" bridges for PEMF stimulation in vitro

[0161] introduction

[0162] Development of passive electrode systems using anodized niobium wires to couple time-varying electrical signals into the culture chamber. The purpose of this design is to replace the traditional electrolyte used to transmit PEMF-like signals (such as those generated capacitively rather than inductively by the EBI repetitive pulse segment bone growth stimulator in in vitro tissue for cell and tissue research). bridge technology to reduce complexity and improve reproducibility. Anodized niobium wire is readily available and requires only simple hand tools to form the electrode bridge. At the available frequencies (typically between 5Hz and 3Hz), the passage of DC current is negligible.

[0163] background

[0164] Capacitively coupled electric fields have generally been introduced into culture media with traditional electrolyte salt bridges, which have limited frequency response...

Embodiment 3

[0174] Stimulation of chondrocytes using capacitively coupled PEMF signals

[0175] introduction

[0176] Clinical applications of PEMF signaling similar to those used for bone repair are currently being tested for their ability to reduce joint pain in arthritic patients. Of interest is whether this pain-reducing signal can also ameliorate the underlying problem of damaged cartilage.

[0177] background

[0178] Compared to drug treatments and biologics, PEMF-based therapeutics offer an easy-to-use non-invasive treatment that contains no foreign agents with potential side effects and has zero washout time. Problems with PEMF therapeutic approaches include: identifying responding cells, elucidating the physical transduction site on the cell, and determining the biological mechanism of the response leading to the cellular response. The aim of this study was to identify the specific PEMF signal currently being tested for pain reduction (MEDRELIEFE , Healthonics, Inc, GA) can...

[0001] Cross application of related applications

[0002] This application claims U.S. Provisional Patent Application 60 / 687,430, filed June 3, 2005, U.S. Provisional Patent Application 60 / 693,490, filed June 23, 2005, U.S. Provisional Patent Application 60 / 782,462, filed March 15, 2006 and priority of US Provisional Patent Application 60 / 790,128, filed April 7, 2006. Background technique

[0003] Diseases and injuries associated with bone and cartilage have a large impact on the human population. Approximately 5 million fractures occur each year in the United States alone. About 10% of these have delayed union, and of these, 150,000 to 200,000 nonunion fractures occur with loss of productivity and independence. In the case of cartilage, severe chronic forms of knee cartilage damage can lead to greater deterioration of the articular cartilage and may eventually lead to replacement of the entire knee joint. Each year, approximately 200,000 total knee replacement surgeries ar...

Examples

Embodiment 1

[0141] Effects of PEMF signaling structure on mineralization and morphology in primary osteoblast cultures

[0142] The goal of this study was to compare two PEMF waveform structures delivered by capacitive coupling by evaluating biochemical and morphological changes in primary osteocyte cultures.

[0143] method

[0144] Osteoblast culture: primary human osteoblasts (CAMBREX , Walkersville, MD) was amplified to 75% confluence (confluence), and seeded directly on the previously described LAB-TEK at a density of 50,000 cells / ml TM (NALGENUNC INTERNATIONAL TM, Rochester, NY) room. Cultures were initially supported on basal osteoblast medium in the absence of differentiation factors. When the cultures reached 70% confluency in house, the medium was supplemented with hydrocortisone-21-hemisuccinate (200 mM final concentration), β-glycerophosphate (10 mM final concentration) and ascorbic acid. At 37°C, 5% CO 2 , Osteoblasts were cultured in humid air under 95% air for 21 day...

Embodiment 2

[0160] Use of niobium "salt" bridges for PEMF stimulation in vitro

[0161] introduction

[0162] Development of passive electrode systems using anodized niobium wires to couple time-varying electrical signals into the culture chamber. The purpose of this design is to replace the traditional electrolyte used to transmit PEMF-like signals (such as those generated capacitively rather than inductively by the EBI repetitive pulse segment bone growth stimulator in in vitro tissue for cell and tissue research). bridge technology to reduce complexity and improve reproducibility. Anodized niobium wire is readily available and requires only simple hand tools to form the electrode bridge. At the available frequencies (typically between 5Hz and 3Hz), the passage of DC current is negligible.

[0163] background

[0164] Capacitively coupled electric fields have generally been introduced into culture media with traditional electrolyte salt bridges, which have limited frequency response...

Embodiment 3

[0174] Stimulation of chondrocytes using capacitively coupled PEMF signals

[0175] introduction

[0176] Clinical applications of PEMF signaling similar to those used for bone repair are currently being tested for their ability to reduce joint pain in arthritic patients. Of interest is whether this pain-reducing signal can also ameliorate the underlying problem of damaged cartilage.

[0177] background

[0178] Compared to drug treatments and biologics, PEMF-based therapeutics offer an easy-to-use non-invasive treatment that contains no foreign agents with potential side effects and has zero washout time. Problems with PEMF therapeutic approaches include: identifying responding cells, elucidating the physical transduction site on the cell, and determining the biological mechanism of the response leading to the cellular response. The aim of this study was to identify the specific PEMF signal currently being tested for pain reduction (MEDRELIEFE , Healthonics, Inc, GA) can...

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