Implantable medical devices having microporous surface layers and method for reducing foreign body response to the same
Inventors
Marshall, Andrew J. • Alvarez, Michel • Maginness, Max
Assignees
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Publication Number
US-8647393-B2
Publication Date
2014-02-11
Expiration Date
Abstract
This disclosure provides implantable devices coated with microporous surface layers with macrotopographic features that improve bio-integration at the interface of the implantable devices and the surrounding tissue.
Core Innovation
The invention relates to implantable medical devices having a microporous surface layer with a macrotopographic surface comprising peaks and valleys. The microporous layer includes a microporous network with interconnected pores and throats that form an open-cell structure, and substantially the pores are each interconnected to at least two other pores via throats, creating a porous and nonporous interface at the macrotopography.
In one implementation, the microporous open-cell structure is a continuously microporous and open-cell coating on a device surface. In another implementation, the textured microporous architecture is a granular macrotextured monolayer, optionally with intermittently nonporous valley floors, forming a porous and nonporous interface at the macrotopography. The macrotopography is defined by peak heights measured from valley floors, with each peak being microporous.
The disclosure presents the microporous macrotopographic architecture as improving bio-integration and reducing foreign body response, including reduced capsule thickness and reduced α-SMA myofibroblasts. The textured microporous interface is further described as improving infection resistance for percutaneous catheter exit sites, including STARcuff use, supported by animal model histology and bacterial challenge results, as well as SEM and histology figures comparing surface geometry.
Claims Coverage
The document contains two independent claims: one directed to a microporous biomaterial and one directed to an implantable device comprising a granule-based textured surface layer. Across these independent claims, the core inventive structure is an open-cell, interconnected microporous pore network with macrotopographic peaks and valleys defined by throat-connected pores and peak height measured from valley floors, with specified micrometer ranges and a granule-based textured layer implementation for the device claim.
Open-cell interconnected microporous peaks-and-valleys biomaterial
A microporous biomaterial with macrotopographic surface features and a plurality of pores, where substantially all pores are interconnected to at least 2 other pores, pores have a mean diameter between about 5 and about 100 micrometers, and any two adjacent pores are connected by a throat with a mean throat diameter between about 5 micrometers and about 50 micrometers; the macrotopography is defined by a plurality of peaks and valleys; each peak is microporous and has a height between about 100 micrometers and about 2000 micrometers; at least two adjacent peaks define a valley having a floor from which the heights of the adjacent peaks are measured; the microporous biomaterial comprises an open-cell structure throughout.
Granule-based textured surface layer overlying an implantable device body
An implantable device comprising a device body and a textured surface layer overlying the device body, wherein the textured surface layer comprises one or more granules of a microporous biomaterial; the granules form a surface macrotopography including a plurality of peaks and valleys; each peak has a height between about 100 micrometers and about 2000 micrometers; each granule comprises a plurality of interconnecting pores having a mean pore diameter between about 5 and 100 micrometers; any two adjacent pores are connected by a throat with a mean throat diameter between 5 and 50 micrometers; and at least two adjacent peaks define a valley having a floor from which the heights of the adjacent peaks are measured.
Claim coverage centers on an implantable-relevant microporous architecture: interconnected pores and throats forming an open-cell structure, combined with macrotopographic peaks and valleys where peak height is defined relative to valley floors, with the device independent claim further specifying a textured surface layer formed by granules of the microporous biomaterial.
Stated Advantages
Improving bio-integration.
Reducing foreign body response, including reduced capsule thickness.
Reducing α-SMA myofibroblasts.
Improving infection resistance for percutaneous catheter exit sites.
Documented Applications
Percutaneous catheter exit sites, including STARcuff, for improved infection resistance.
Implantable devices described with the microporous macrotopographic architecture for promoting angiogenesis.
Implantation to reduce foreign body response associated with an implantable device.
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