[nanoPost] Artificial vascular access grafts

Company Israel

- The company currently pursues validation of its technology via its clinical-phase product – the artificial vascular access graft for end stage renal disease (ESRD) patients, called an artificial Arterio-Venous Shunt (AV-Shunt).

- Due to its early access & self-sealing properties, the company believes it will be addressing the critical unmet needs of artificial vascular access grafts. Preclinical studies have demonstrated its potential for unparalleled performance, including puncture-resistance and early-access properties that are superior to the gold standard ePTFE grafts.

- Formation of nanometric-scale fibers is essentially based on one method - electrocapilary spinning (in short - electrospinning) of nano-fibers from polymer solutions and melts. It has been reported in the literature that more than 30 different polymer types including PA, PP, PE, PAN, PEO, PVA, PLA, aramids, polyaniline, synthetic polypeptides, collagen, elastin, fibrinogen, DNA and other biomaterials have been electrospun.

- The application areas for nano-sized fibers include high performance and multifunctional filters, smart surfaces of medical textiles, scaffolds in tissue engineering, separators for chemical sources of current, functional coatings on flexible and hard substrates, building electronic circuits nano-composites etc.
 

- The Company believes that there are four major factors differentiating itself in the arena of electrospinning. These factors are (a) a wide Intellectual Property portfolio (partly pending), (b) unique know-how, (c) automated fabrication capabilities, and (d) application development skills in the medical device field.

- In spite of the fact that basic process of electrospinning has been known since the 1930' , the challenge of implementing to commercial applications requiring high level of reproducibility has probably not been met yet.

- Electrospinning is clearly perceived as a prominent technology for creating nanofiber matrices and thus numerous research groups and some commercial organizations are trying to refine their know-how of the theoretical and practical aspects of it. This is done, however, in very specific contexts (e.g. collagen electrospinning, etc.). It is the Company's understanding that there is no one-place that holds a sufficient knowledge base to enable implementing the technology to a variety of processes, using a range of polymers (synthetic as well as biologic, degradable, as well as stable) and obtain the desired end results with a limited amount of resources put into the development process.

- Electrospinning involves a multitude of scientific and engineering disciplines - chemistry, electrochemistry, high-field electricity, fluid dynamics, material sciences, electrical and mechanical engineering, to name a few. Moreover, the degrees of freedom in the electrospinning process are numerous and the inter-relations between process parameters are non trivial. That may explain the slow penetration rate of electrospinning into commercial applications.

Product: Vascular Access Graft

- product is a 6 mm vascular graft, made of a matrix of Poly-Urethane nanometric scale fibers.

- The graft is designed to self-seal following a needle puncture, which should enable its use as an early access graft. Combined with unique EM² TM design, promoting endothelialization of the graft, the company believe will be an important step forward in the field of vascular access devices.

- Self-Sealing: Resulting from its unique elastic nanofiber design, the vascular graft tends to self-seal following a needle puncture. This basic feature should enable its use as an early-access graft, as well as reduce the incidence of pseudo-aneurysms and the need for thrombolytics treatments.

- Bench tests (data on file) have demonstrated that the Nicast's graft leaks at approx. 20-fold higher hydrostatic pressure compared to commercial ePTFE grafts. An added benefit to the self-sealing property lies in the fact that suturing the graft isn't accompanied by suture-line "tearing" and therefore requires no special suture and can enable closing of the surgical field soon after the anastomoses have been performed.

- EM² (Endoluminal Matrix Morphology) for Enhanced Endothelialization
The internal lumen of  graft is designed to have a highly interconnected open pore structure with pores in the range of a few micrometers. Created using proprietary electrospinning technology and defined EM², this unique design creates a bio-mimetic scaffold and provides a highly suitable substrate for durable in-vivo endothelialization.

- Superior Mechanical Properties: The vascular graft is made of the highly elastic PolyUrethane. Together with the nanofiber wall design, this given the graft an elastic range that is much higher than ePTFE products, both in the longitudinal and radial directions - enabling the graft to be as pulsatile as an artery and to reversibly stretch in the axial direction, without residual elongation. This can represent a significantly improvement when it is required to pass the graft across joints, as the tensile stress is evenly distributed over the entire graft length, instead of at the anastomoses.