Applications of synthetic polymers in clinical medicine

This review presents an overview of “Lab on Fiber” technologies and devices with special focus on the design and development of advanced fiber optic nanoprobes for biological applications. Depending on the specific location where functional materials at micro and nanoscale are integrated, “Lab on Fiber Technology” is classified into three main paradigms: Lab on Tip (where functional materials are integrated onto the optical fiber tip), Lab around Fiber (where functional materials are integrated on the outer surface of optical fibers), and Lab in Fiber (where functional materials are integrated within the holey structure of specialty optical fibers).

This work reviews the strategies, the main achievements and related devices developed in the “Lab on Fiber” roadmap, discussing perspectives and challenges that lie ahead, with special focus on biological sensing applications.

Lab on Fiber Technology for biological sensing applications

The flat tip of an optical fiber is a unique and unconventional platform for micro and nanotechnologies The small cross-section and large aspect ratio of the fiber provide an inherently light-coupled substrate that is uniquely suited to remote, in vivo and in situ applications However, these same characteristics challenge established fabrication technologies, which are best suited to large planar substrates This review presents a broad overview of strategies for patterning the flat tip of an optical fiber Techniques discussed include self-assembly, numerous lithographies, through-fiber patterning, hybrid techniques, and strategies for mass manufacture, while the diverse applications are discussed in context throughout

The Optical Fiber Tip: An Inherently Light-Coupled Microscopic Platform for Micro- and Nanotechnologies

Biofunctionalization of metallic implants by calcium phosphate coatings.

The integration of microfluidics and photonic biosensors has allowed achievement of several laboratory functions in a single chip, leading to the development of photonic lab-on-a-chip technology. Although a lot of progress has been made to implement such sensors in small and easy-to-use systems, many applications such as point-of-care diagnostics and in vivo biosensing still require a sensor probe able to perform measurements at precise locations that are often hard to reach. The intrinsic property of optical fibers to conduct light to a remote location makes them an ideal platform to meet this demand. The motivation to combine the good performance of photonic biosensors on chips with the unique advantages of optical fibers has thus led to the development of the so-called lab-on-fiber technology. This emerging technology envisages the integration of functionalized materials on micro- and nano-scales (i.e. the labs) with optical fibers to realize miniaturized and advanced all-in-fiber probes, especially useful for (but not limited to) label-free chemical and biological applications. This review presents a broad overview of lab-on-fiber biosensors, with particular reference to lab-on-tip platforms, where the labs are integrated on the optical fiber facet. Light-matter interaction on the fiber tip is achieved through the integration of thin layers of nanoparticles or nanostructures supporting resonant modes, both plasmonic and photonic, highly sensitive to local modifications of the surrounding environment. According to the physical principle that is exploited, different configurations - such as localized plasmon resonance probes, surface enhanced Raman scattering probes and photonic probes - are classified, while various applications are presented in context throughout. For each device, the surface chemistry and the related functionalization protocols are reviewed. Moreover, the implementation strategies and fabrication processes, either based on bottom-up or top-down approaches, are discussed. In conclusion we highlight some of the further development opportunities, including lab-in-a-needle technology, which could have a direct and disruptive impact in localized cancer treatment applications.

Lab-on-fiber technology: a new vision for chemical and biological sensing

http://www.angiogenesis-center.org/documents/rat%20aorta%20stent.pdf

Paclitaxel/sirolimus combination coated drug-eluting stent: In vitro and in vivo drug release studies

A novel fabrication method for surface-enhanced Raman scattering (SERS) sensors that used a fast femtosecond (fs) laser scanning process to etch uniform patterns and structures on the endface of a fused silica optical fiber, which is then coated with a thin layer of silver through thermal evaporation is presented. A high quality SERS signal was detected on the patterned surface using a Rhodamine 6G (Rh6G) solution. The uniform SERS sensor built on the tip of the optical fiber tip was small, light weight, and could be especially useful in remote sensing applications.

Surface-Enhanced Raman Scattering Sensor on an Optical Fiber Probe Fabricated with a Femtosecond Laser

Over the past decade, drug-eluting stents (DES) have greatly transformed the field of interventional cardiology. Generally, three components are included in a DES system: a metal stent platform, a drug carrier or so called ‘stent coating’ and a drug. As such, stent coating plays an important role in the performance of DES. This article will review the evolution of stent coatings and their role in the development of restenosis and thrombosis.

/pdf/drug-eluting-stent-coatings-2i7dul9bm6.pdf

Drug-eluting stent coatings

The purpose of this study was to optimize a novel biodegradable polymer for drug eluting stent (DES) applications. Degradation profiles of different poly(D,L-lactide-co-glycolide)/amorphous calcium phosphate (PLGA/ACP) composites coated on stents were studied both in vitro and in vivo for three months. For the in vitro study, stents were immersed into the phosphate buffered saline (37 °C, pH 7.4) with constant shaking. The polymer weight loss was measured weekly and morphological changes were analyzed. The results demonstrated that approximately 60% of polymer was degraded within the three-month period and there was no significant difference between the different PLGA/ACP composites. However, the composite of 50% PLGA (65/35) with 50% ACP showed a slightly faster degradation rate than other composites. Morphologically, all stent surfaces changed from a micro-porous before degradation to a corrugated solid micro-net-like structure at two months post degradation. Based on in vitro results, 65% PLGA (65/35) with 35% ACP) coated stents were selected and implanted into rat aortas (n = 12) for the in vivo study. Microscopic observation showed that no composite was found on any of the implanted stents at 12 weeks post implantation, which indicated the selected PLGA/ACP composite is desired for DES applications.

/pdf/in-vitro-and-in-vivo-degradation-of-poly-d-l-lactide-co-1dvfoz24gt.pdf

In vitro and in vivo degradation of poly(D, L-lactide-co-glycolide)/amorphous calcium phosphate copolymer coated on metal stents.

Triple-negative breast cancer (TNBC) is still the most aggressive cancer in women. Combination chemotherapy holds great potential for cancer therapy; however, the off-target and side effects of free chemotherapy administration remain a major challenge. In this study, we developed a photo/thermo-responsive nanoplatform that can be used for TNBC treatment via photothermic therapy in combination with multidrug therapy. By conjugating the chemotherapy drug PTX prodrug on the surface of mesoporous silica-coated gold nanorod nanoparticles and then loading another chemotherapy drug, CPT, the Au@MSN-PTX@CPT nanoparticles exhibited great photothermal response, redox response drug release and cancer cell inhibition abilities. Otherwise, we further coated the Au@MSN-PTX@CPT nanoparticle with a temperature-sensitive polymer poly(N-isopropylacrylamide-co-methacrylic acid) (p(NIPAM-co-MAAc)), and the polymer-coated Au@MSN-PTX@TPT@polymer nanoparticles showed perfect near-infrared (NIR) light controlled drug release. Finally, the Au@MSN-PTX@CPT@polymer nanoparticles were injected into the 4T1 breast cancer mouse model. The Au@MSN-PTX@CPT@polymer nanoparticles preferably accumulated at the tumor site and had reduced chemotherapy injuries and great antitumor activity when combined with 650 nm laser treatment. In summary, our developed Au@MSN-PTX@CPT@polymer nanoparticles served as a good method for controlled chemodrug delivery and provided a good choice for TNBC combination therapy. 

Xiaodong Ma

Papers

Paclitaxel/sirolimus combination coated drug-eluting stent: In vitro and in vivo drug release studies

Surface-Enhanced Raman Scattering Sensor on an Optical Fiber Probe Fabricated with a Femtosecond Laser

Drug-eluting stent coatings

In vitro and in vivo degradation of poly(D, L-lactide-co-glycolide)/amorphous calcium phosphate copolymer coated on metal stents.

Co‐delivery CPT and PTX prodrug with a photo/thermo‐responsive nanoplatform for triple‐negative breast cancer therapy