Eudragit S100 coated nanodiamond-based nanoparticles as an oral chemo-photothermal delivery system for local treatment of colon cancer.

Oral colonic nano-drug delivery system has received more and more attention in the treatment of colon cancer due to local precision treatment and reduction of drug system distribution. However, the complex and harsh gastrointestinal environment and the retention of nanoparticles in the colon limit its development. To this end, we designed Eudragit S100 (ES) coated nanoparticles (ES@PND-PEG-TPP/DOX). Polydopamine coated nanodiamond (PND) was modified with amino-functionalized polyethylene glycol (NH2-PEG-NH2) and triphenylphosphine (TPP) successively. Due to the high specific surface area of PND, it can efficiently load the model drug doxorubicin hydrochloride (DOX). In addition, PND also has high photothermal conversion efficiency, generating heat to kill cancer cells under near infrared (NIR) laser, realizing the combination of chemotherapy and photothermal therapy (CT-PTT). TPP modification enhanced nanoparticle uptake by colon cancer cells and prolonged preparations retention time at the colon. ES shell protected the drug from being destroyed and prevented the nanoparticles from sticking to the small intestine. Ex vitro fluorescence imaging showed that TPP modification can enhance the residence time of nanoparticles in the colon. In vivo pharmacodynamics demonstrated that CT-PTT group has the greatest inhibitory effect on tumor growth, which means that the nanocarrier has potential clinical value in the in-situ treatment of colon cancer.

Multifunctional Therapeutic Nanodiamond Hydrogels for Infected-Wound Healing and Cancer Therapy.

Wound infection and tumor recurrence are the two main threats to cancer patients after surgery. Although researchers have developed new treatment systems to address the two significant challenges simultaneously, the potential side effects of the heavy-metal-ion-based treatment systems still severely limit their widespread application in therapy. In addition, the wounds from tumor removal compared with general operative wounds are more complex. The tumor wounds mainly exhibit more hemorrhage, larger trauma area, greater vulnerability to bacterial infection, and residual tumor cells. Therefore, a multifunctional treatment platform is urgently needed to integrate rapid hemostasis, sterilization, wound healing promotion, and antitumor functions. In this work, nanodiamonds (NDs), a material that has been well proven to have excellent biocompatibility, are added into a solution of acrylic-grafted chitosan (CEC) and oxidized hyaluronic acid (OHA) to construct a multifunctional treatment platform (CEC-OHA-NDs). The hydrogels exhibit rapid hemostasis, a wound-healing-promoting effect, excellent self-healing, and injectable abilities. Moreover, CEC-OHA-NDs can effectively eliminate bacteria and inhibit tumor proliferation by the warm photothermal effect of NDs under tissue-penetrable near-infrared laser irradiation (NIR) without cytotoxicity. Consequently, we adopt a simple and convenient strategy to construct a multifunctional treatment platform using carbon-based nanomaterials with excellent biocompatibility to promote the healing of infected wounds and to inhibit tumor cell proliferation simultaneously.

Luminescent quantum dots: Synthesis, optical properties, bioimaging and toxicity.

Luminescent nanomaterials such as semiconductor nanocrystals (NCs) and quantum dots (QDs) attract much attention to optical detectors, LEDs, photovoltaics, displays, biosensing, and bioimaging. These materials include metal chalcogenide QDs and metal halide perovskite NCs. Since the introduction of cadmium chalcogenide QDs to biolabeling and bioimaging, various metal nanoparticles (NPs), atomically precise metal nanoclusters, carbon QDs, graphene QDs, silicon QDs, and other chalcogenide QDs have been infiltrating the nano-bio interface as imaging and therapeutic agents. Nanobioconjugates prepared from luminescent QDs form a new class of imaging probes for cellular and in vivo imaging with single-molecule, super-resolution, and 3D resolutions. Surface modified and bioconjugated core-only and core-shell QDs of metal chalcogenides (MX; M = Cd/Pb/Hg/Ag, and X = S/Se/Te,), binary metal chalcogenides (MInX2; M = Cu/Ag, and X = S/Se/Te), indium compounds (InAs and InP), metal NPs (Ag, Au, and Pt), pure or mixed precision nanoclusters (Ag, Au, Pt), carbon nanomaterials (graphene QDs, graphene nanosheets, carbon NPs, and nanodiamond), silica NPs, silicon QDs, etc. have become prevalent in biosensing, bioimaging, and phototherapy. While heavy metal-based QDs are limited to in vitro bioanalysis or clinical testing due to their potential metal ion-induced toxicity, carbon (nanodiamond and graphene) and silicon QDs, gold and silica nanoparticles, and metal nanoclusters continue their in vivo voyage towards clinical imaging and therapeutic applications. This review summarizes the synthesis, chemical modifications, optical properties, and bioimaging applications of semiconductor QDs with particular references to metal chalcogenide QDs and bimetallic chalcogenide QDs. Also, this review highlights the toxicity and pharmacokinetics of QD bioconjugates.

Synthesis of Multi-Stimuli Responsive Fe3O4 Coated with Diamonds Nanocomposite for Magnetic Assisted Chemo-Photothermal Therapy.

Nanodiamonds with magnetic resonance imaging (MRI) and targeted drug delivery to exert combined effects for biomedical applications have been considered to be an urgent challenge. Herein, a novel bio-nanoarchitectonics (Fe3O4@NDs) with simultaneous imaging and therapeutic capacities was fabricated by covalently conjugating nanodiamonds (NDs) with Fe3O4. Fe3O4@NDs exhibited better biocompatibility and excellent photothermal stability with superb photothermal conversion performance (37.2%). Fe3O4@NDs has high doxorubicin (DOX) loading capacity (193 mg/g) with pH and NIR-responsive release characteristics. Fe3O4@NDs loading DOX showed a combined chemo-photothermal inhibitory effect on the tumor cells. Enhanced T2-weighted MRI contrast toward the tumor, with the assistance of a magnetic field, convinced the Fe3O4@NDs gathered in the tumor more efficiently and could be used for MRI-based cancer diagnosis. Our results revealed an effective strategy to achieve a stimuli-sensitive nanoplatform for multifunctional theranostics by the combined action.

Screening of anti-cancerous potential of classical Raudra rasa and modified Raudra rasa modified with hiraka bhasma (nanodiamond) through FTIR & LC-MS analysis.

OBJECTIVES: Raudra rasa is an ayurvedic medicine explicitly prescribed for the treatment of arbuda (cancer), whereas hiraka bhasma has the potential to promote cancer healing properties. Together, these two medicines provide multifunction benefits. This paper analyses the functional groups of Raudra rasa modified with hiraka bhasma and compares it with the classically prepared raudra rasa. To identify the functional group, organic ligands, and active compounds present in samples of raudra rasa (CRR) and modified raudra rasa with hiraka bhasma (MRR) contributing to cancer alleviation by using Fourier transform infrared spectroscopy (FTIR) & LC-MS analysis. METHODS: Classical raudra rasa (CRR), its ingredients, shadguna kajjali (SK); decoction of Piper betel Linn. (PBD); Amaranthus spinosus Linn. (ASD); Boerhaavia diffusa Linn. (BDD); Piper longum Linn. (PLD); cow urine (GM), & similarly modified raudra rasa (MRR), its ingredients, hiraka bhasma (HB); shadguna rasasindura (SHR); water-soluble extract of Piper betel Linn. (PBE); Amaranthus spinosus Linn. (ASE); Boerhaavia diffusa Linn. (BDE); cow urine ark (GA); Piper Longum Linn. (PLE) were subjected to FTIR and LC-MS analysis. RESULTS: Among all 15 samples studied, maximum numbers of peaks (21) were seen in MRR indicating a greater number of functional groups. Further, in MRR, a maximum peak in the double bond region is suggestive of its higher stability compared to CRR. Both the compound is preliminarily a mixture of the number of functional groups like; fluoro, methyl, amino, hydroxy, nitro, methylamino, carbonyl, and iodo groups, having known anti-proliferative activities. By the FT-IR analysis, the biologically active compounds in aqueous and methanol extract of CRR & MRR were identified that have anti-cancerous compounds. In the present study, a total of 40 major compounds like alkaloids, amino acid, carboxylic acid, Flavonoids, Nucleoside, Nucleotide, phenylpropanoid, Sphingosine, stilbenoid, sugar, phosphate, terpenoids, vitamin from aqueous & methanol extract of CRR & MRR were identified by LC-MS. CONCLUSIONS: This research paper highlights the presence of different functional groups and bioactive compounds known to have anti-cancer activities. Thus, this review suggests future recommendations for the design and development of improved anticancer drugs with higher efficacy.

Nanodiamond-based multifunctional platform for oral chemo-photothermal combinational therapy of orthotopic colon cancer.

Combination therapy system has become a promising strategy for achieving favorable antitumor efficacy. Herein, a novel oral drug delivery system with colon localization and tumor targeting functions was designed for orthotopic colon cancer chemotherapy and photothermal combinational therapy. The polydopamine coated nanodiamond (PND) was used as the photothermal carrier, through the coupling of sulfhydryl-polyethylene glycol-folate (SH-PEG-FA) on the surface of PND to achieve systematic colon tumor targeting, curcumin (CUR) was loaded as the model drug, and then coated with chitosan (CS) to achieve the long gastrointestinal tract retention and colon localization functions to obtain PND-PEG-FA/CUR@CS nanoparticles. It has high photothermal conversion efficiency and good photothermal stability and exhibited near-infrared (NIR) laser-responsive drug release behavior. Folate (FA) modification effectively promotes the intracellular uptake of nanoparticles by CT26 cells, and the combination of chemotherapy and photothermal therapy (CT/PTT) can enhance cytotoxicity. Compared with free CUR group, nanoparticles prolonged the gastrointestinal tract retention time, accumulated more in colon tumor tissues, and exhibited good photothermal effect in vivo. More importantly, the CT/PTT group exhibited satisfactory tumor growth inhibition effects with good biocompatibility in vivo. In summary, this oral drug delivery system is an efficient platform for chemotherapy and photothermal combinational therapy of orthotopic colon cancer.

Recent Advancements in Nanodiamond Mediated Brain Targeted Drug Delivery and Bioimaging of Brain Ailments: A Holistic Review.

BACKGROUND: The brain is a vital and composite organ. By nature, the innate make-up of the brain is such that in anatomical parlance, it is highly protected by the "Blood-Brain Barrier", which is a nexus of capillary endothelial cells, basement membrane, neuroglial membrane and glialpodocytes. The same barrier, which protects and isolates the interstitial fluid of the brain from capillary circulation, also restricts the therapeutic intervention. Many standing pharmaceutical formulations are ineffective in the treatment of inimical brain ailments because of the inability of the API to surpass and subsist inside the Blood Brain Barrier. OBJECTIVE: This is an integrated review that emphasizes on the recent advancements in brain-targeted drug delivery utilizing nanodiamonds (NDs) as a carrier of therapeutic agents. NDs are a novel nanoparticulate drug delivery system, having carbon moieties as their building blocks and their surface tenability is remarkable. These neoteric carbon-based carriers have exceptional, mechanical, electrical, chemical, optical, and biological properties, which can be further rationally modified and augmented. DISCUSSION: NDs could be the next"revolution "in the field of nanoscience for the treatment of neurodegenerative disorders, brain tumors, and other pernicious brain ailments. What sets them apart from other nanocarriers is their versatile properties like diverse size range and surface modification potential, which makes them efficient enough to move across certain biological barriers and offer a plethora of brain targeting and bioimaging abilities. CONCLUSION: The blood-brain barrier (BBB) poses a major hurdle in the way of treating many serious brain ailments. A range of nanoparticle based drug delivering systems have been formulated, including solid lipid nanoparticles, liposomes, dendrimers, nanogels, polymeric NPs, metallic NPs (gold, platinum, andironoxide) and diamondoids (carbonnanotubes). Despite this development, only a few of these formulations have shown the ability to cross the BBB. Nanodiamonds, because of their small size, shape, and surface characteristics, have a potential in moving beyond the diverse and intricate BBB, and offer a plethora of brain targeting capabilities.

A multifunctional nanodiamond-based nanoplatform for the enhanced mild-temperature photothermal/chemo combination therapy of triple negative breast cancer via an autophagy regulation strategy.

Owing to its aggressive biological behavior, the lack of specific targets, and the strong therapeutic resistance of triple negative breast cancer (TNBC), current therapeutic strategies are still limited. The combination of multiple treatments has been confirmed as a promising strategy for TNBC therapy. However, the efficacy of combination therapy can be restricted due to increasing therapeutic resistance to various treatments. Herein, we constructed a nanodiamond (ND)-based nanoplatform for augmented mild-temperature photothermal/chemo combination therapy against TNBC, weakening the therapeutic resistance via autophagy inhibition enabled by the NDs. A layer-by-layer self-assembly approach was utilized to construct the ND-based nanoplatform. First, the NDs were modified with protamine sulphate (PS). Meanwhile, the photosensitizer indocyanine green (ICG) and the HSP70 small molecule inhibitor apoptozole (APZ) could be synchronously incorporated to form positively charged PS@ND (ICG + APZ). Then negatively charged hyaluronic acid (HA) was assembled onto the outer face of PS@ND (ICG + APZ) to form the NPIAs. Finally, the positively charged small molecule anti-cancer drug doxorubicin (DOX) could be adsorbed onto the surface of the NPIAs through electrostatic interactions (NPIADs). The resulting NPIADs could be triggered by NIR laser irradiation to exhibit enhanced mild-temperature photothermal therapy (PTT) effects via suppressing the expression of HSP70, and PTT combined with chemotherapy could further enhance the anti-tumor efficacy. Subsequently, the sensitivity of MDA-MB-231 cells could be significantly improved through the weakening of the thermal/drug resistance via autophagy inhibition, leading to augmented combination therapy that is efficient both in vitro and in vivo. Furthermore, the NPIADs could be used as a theranostic nanoplatform for fluorescence (FL) and photoacoustic (PA) imaging. Taken together, this study demonstrated a multifunctional ND-based nanoplatform for FL/PA imaging-guided augmented mild-temperature photothermal/chemo combination therapy via an autophagy regulation strategy against TNBC.

Nanodiamonds synthesis using sustainable concentrated solar thermal energy: applications in bioimaging and phototherapy.

There is a renewed interest in nanodiamonds and their applications in biology and medicine, especially in bioimaging and photothermal therapy. This is due to their small size, chemical inertness and unique photo-properties such as bright and robust fluorescence, resistant to photobleaching and photothermal response under near infrared (NIR) irradiation. However, the biggest challenge limiting the wide-spread use of nanodiamonds is the high-energy consuming, dangerous and sophisticated synthetic methods currently adopted by industry named higher temperature high pressure approach, and detonation method. Despite over a decade of research towards the development of new synthetic approaches, most of the methods developed to date require sophisticated instrumentations and have high energy demand. To circumvent the reliance on high energy demanding sophisticated experimental setups, here we present a simple synthetic approach using solar energy as a sustainable sole energy source. Using low-grade coal as carbon precursor, we used high power magnifying glasses to concentrate and focus sunlight to induce synthesis of nanodiamonds. The synthesized nanodiamonds exhibit similar physicochemical and photo-properties as nanodiamonds synthesized using other synthetic approaches.In vitrostudies using macrophage Raw 264.7 cells demonstrated rapid uptake and bright fluorescence of the synthesized nanodiamonds with superior biocompatibility (≥95% cell viability). The synthesized nanodiamonds also exhibited dose dependent photothermal response under NIR irradiation.

Self-assembling combretastatin A4 incorporated protamine/nanodiamond hybrids for combined anti-angiogenesis and mild photothermal therapy in liver cancer.

Tumor angiogenesis has been identified as an important factor in the development and progression of tumors, and anti-angiogenesis therapy has been recognized as an effective tumor therapy pattern. The unique characteristics of nanodiamonds (NDs) have been explored for photothermal therapy (PTT) against cancer, while the efficiency of mild PTT mediated by bare NDs was limited. The combination of different therapies into a single nanoplatform has shown great potential for synergistic cancer treatment. In this investigation, we integrated hydrophobic antiangiogenesis agent combretastatin A4 (CA4) into the protamine sulfate (PS) functionalized NDs hybrids (NDs@PS) with a noncovalent self-assembling method (CA4-NDs@PS) for potential combined anti-angiogenesis and mild PTT in liver cancer. The resulted CA4-NDs@PS NDs exhibited high drug loading ability, good dispersibility and colloidal stability. The near-infrared (NIR) laser irradiation could trigger the release of CA4 from CA4-NDs@PS NDs and elevate the temperature of CA4-NDs@PS NDs aqueous solution.In vitroresults illustrated that CA4-NDs@PS coupled with laser irradiation could remarkably enhance HepG-2 cells killing efficiency, leading to an enhanced photocytotoxicity. Furthermore,in vivoexperiments revealed that CA4-NDs@PS exhibited a highly synergistic anticancer efficacy with NIR laser irradiation in HepG-2 tumor-bearing mice. Altogether, our present study fabricated a novel NDs@PS-based nanoplatform for combined anti-tumor angiogenesis and mild PTT against liver cancer.

Multicomponent-assembled nanodiamond hybrids for targeted and imaging guided triple-negative breast cancer therapy via a ternary collaborative strategy.

Uniting combinational strategies has been confirmed to be a robust choice for high-performance cancer treatment due to their abilities to overcome tumor heterogeneity and complexity. However, the development of a simple, effective, and multifunctional theranostics nanoplatform still remains a challenge. In this study, we integrated multicomponent hyaluronic acid (HA), protamine (PS), nanodiamonds (NDs), curcumin (Cur), and IR780 into a single nanoplatform (denoted as HPNDIC) based on the combination of hydrophobic and electrostatic noncovalent interactions for dual-modal fluorescence/photoacoustic imaging guided ternary collaborative Cur/photothermal/photodynamic combination therapy of triple-negative breast cancer (TNBC). A two-step coordination assembly strategy was utilized to realize this purpose. In the first step, PS was utilized to modify the NDs clusters to form positively charged PS@NDs (PND) and the simultaneous encapsulation of the natural small-molecule drug Cur and the photosensitive small-molecule IR780 (PNDIC). Second, HA was adsorbed onto the outer surface of the PNDIC through charge complexation for endowing a tumor-targeting ability (HPNDIC). The resulting HPNDIC had a uniform size, high drug-loading ability, and excellent colloidal stability. It was found that under the near-infrared irradiation condition, IR780 could be triggered to exhibit both PTT/PDT dual-pattern therapy effects, leading to an enhanced therapy efficiency of Cur both in vitro and in vivo with good biocompatibility. Due to the intrinsic imaging property of IR780, the biodistribution and accumulation behavior of HPNDIC in vivo could be monitored by dual-modal fluorescence/photoacoustic imaging. Taken together, our current work demonstrated the assembly of a NDs-based multicomponent theranostic platform for dual-modal fluorescence/photoacoustic imaging guided triple-collaborative Cur/photothermal/photodynamic against TNBC.

Polyethyleneimine-Functionalized Magnetic Fe3O4 and Nanodiamond Particles as a Platform for Amoxicillin Delivery.

Antibiotics are used to treat many infectious diseases such as urinary tract infection. However, the resistance to antibiotic can increase due to the high-dose exposure to the human body. Alternative methods to lower the dosage of the antibiotics and deliver it to the specific organ are required for a more effective delivery and treatment at much lower dosage. A stable loading of amoxicillin on purified and polyethyleneimine-functionalized nano diamond particles is used along with magnetic nanoparticles for drug delivery in this study. This novel approach is expected to expand the scope of using nano diamond for targeted drug delivery in which nanodiamond is combined with a ferromagnetic material such as Fe3O4 to deliver a specific drug to a particular site using an external magnetic field. To this end, the synthesis and loading of the amoxicillin on Fe3O4 nanoparticles and combining it with nanodiamond-polyethyleneimine-amoxicillin is investigated in this research. Fe3O4 magnetic nanoparticles of cubic spinel structure are synthesized by microwave-assisted techniques, and different combinations of polyethyleneimine loaded ND and Fe3O4 are studied. It is shown that a structural configuration consisting of the core of magnetic particles with nanodiamond and polyethyleneimine can load 40 mg of amoxicillin and gradually released it in different media. The results on drug loading and release kinetics are studied and discussed in this paper.

Boron-Doped Nanodiamonds as Anticancer Agents: En Route to Hyperthermia/Thermoablation Therapy.

Local targeted "inside-out" hyperthermia of tumors via nanoparticles is able to sensitize tumor cells to chemotherapy, radiation therapy, gene therapy, immunotherapy, or other effects, significantly reducing the duration and intensity of treatment. In this article, new nanomaterials are proposed to be used as anticancer agents: boron-doped nanodiamonds with sizes of about 10 nm synthesized for the first time by the high-temperature high-pressure (HTHP) method. The heating ability of boron-doped nanodiamonds was investigated under different heating conditions in different environments: water, chicken egg white, and MCF-7 breast cancer cells. It was discovered that, with the same conversion of the absorbed energy into heat, the ability to heat the environment when excited at a wavelength of 808 nm of boron-doped nanodiamonds is much higher than that of detonation nanodiamonds. It was established that boron-doped nanodiamonds are extremely promising for carrying out hyperthermia and thermoablation of tumors.

Nanodiamond uptake in colon cancer cells: the influence of direction and trypsin-EDTA treatment.

Nanoparticles are routinely used in cell biology. They deliver drugs or function as labels or sensors. For many of these applications it is essential that the nanoparticles enter the cells. While some cell types readily ingest all kinds of particles, others just don't. We report that uptake can be enhanced for some cells if the particles are administered from the basolateral side of the cells (in this case from below). Compared to apical uptake (from above), we report an 8-fold increase in the number of fluorescent nanodiamonds internalized by the colon cancer cell line HT29. Up to 96% of the cells treated by a modified protocol contain at least one nanodiamond, whereas in the control group we could observe nanodiamonds in less than half of the cells. We were also able to show that simple treatment of cell clusters with trypsin-EDTA leads to the same enhancement of the nanodiamond uptake as seeding the cells on top of the nanoparticles. Although our study is focused on nanodiamonds in HT29 cells, we believe that this method could also be applicable for other nanoparticles and cells with a specific directionality.

Polyaniline-grafted nanodiamonds for efficient photothermal tumor therapy.

Polyaniline-grafted nanodiamond (PAN-ND) nanoparticles were fabricated by polymerizing aniline at the surface of amine-modified NDs for efficient photothermal therapy (PTT). A series of PAN from different aniline concentrations were also prepared to compare the properties and the efficiency of PTT. The polymerization rate of aniline was faster in the presence of NDs than that of aniline alone. Compared to PAN nanoparticles, PAN-ND has a spherical shape, smaller size, and ultimately higher cellular uptake efficiency. The temperature of aqueous PAN-ND dispersion increased to 44.4 °C after laser irradiation for 5 min. In addition, the UV absorbance intensity of PAN-ND increased at the lower pH at the near infrared (NIR) region, resulting in an enhanced photothermal effect at a tumor site. Notably, the viability of HeLa cells treated with PAN-ND decreased by less than 20%, suggesting the high efficiency of PTT. The PAN-ND can be a potential candidate for efficient photothermal tumor therapy.

Electrochemical biosensor made with tyrosinase immobilized in a matrix of nanodiamonds and potato starch for detecting phenolic compounds.

The envisaged ubiquitous sensing and biosensing for varied applications has motivated materials development toward low cost, biocompatible platforms. In this paper, we demonstrate that carbon nanodiamonds (NDs) can be combined with potato starch (PS) and be deposited on a glassy carbon electrode (GCE) in the form of a homogeneous, rough film, with electroanalytical performance tuned by varying the relative ND-PS concentration. As a proof of concept, the ND/PS film served as matrix to immobilize tyrosinase (Tyr) and the resulting Tyr-ND-PS/GCE biosensor was suitable to detect catechol using differential pulse voltammetry with detection limit of 3.9 × 10-7 mol L-1 in the range between 5.0 × 10-6 and 7.4 × 10-4 mol L-1. Catechol could also be detected in river and tap water samples. This high sensitivity, competitive with biosensors made with more sophisticated procedures and materials in the literature, is attributed to the large surface area and conductivity imparted by the small NDs (<5 nm). In addition, the ND-PS matrix may have its use extended to immobilize other enzymes and biomolecules, thus representing a potential biocompatible platform for ubiquitous biosensing.

A new magnetic nanodiamond/graphene oxide hybrid (Fe3O4@ND@GO) material for pre-concentration and sensitive determination of sildenafil in alleged herbal aphrodisiacs by HPLC-DAD system.

A sensitive analytical methodology was investigated to concentrate and determine of sildenafil citrate (SLC) present at trace level in herbal supplementary products. The proposed method is based on simple and sensitive pre-concentration of SLC by using magnetic solid phase extraction with new developed magnetic nanodiamond/graphene oxide hybrid (Fe3O4@ND@GO) material as a sorbent. Experimental variables affecting the extraction efficiency of SLC like; pH, sample volume, eluent type and volume, extraction time and amount of adsorbent were studied and optimized in detail. Determination of sildenafil citrate after magnetic solid phase extraction (MSPE) was carried out by HPLC-DAD system. The morphology, composition, and properties of the synthesized hybrid material was characterized by Fourier transform infrared spectrometry (FT-IR), Raman spectrometry (Raman), X-ray diffraction spectrometry (XRD), scanning electron microscopy (SEM), mapping photographs, zeta potential analyzer, and BET surface area analysis. Under optimized conditions, linear range was ranged from 5.00 to 250.00 ng mL-1 with R2 of 0.9952. The limit of detection (LOD) was 1.49 ng mL-1 and the recoveries at two spiked levels were ranged from 94.0 to 104.1% with the relative standard deviation (RSD) < 7.1% (n = 5). The enhancement factor (EF) was 86.9. The results show that the combination MSPE with HPLC-DAD is a suitable and sensitive method for the determination of SLC in real samples.

Nanodiamond-Gutta Percha Composite Biomaterials for Root Canal Therapy.

Root canal therapy (RCT) represents a standard of treatment that addresses infected pulp tissue in teeth and protects against future infection. RCT involves removing dental pulp comprising blood vessels and nerve tissue, decontaminating residually infected tissue through biomechanical instrumentation, and root canal obturation using a filler material to replace the space that was previously composed of dental pulp. Gutta percha (GP) is typically used as the filler material, as it is malleable, inert, and biocompatible. While filling the root canal space with GP is the standard of care for endodontic therapies, it has exhibited limitations including leakage, root canal reinfection, and poor mechanical properties. To address these challenges, clinicians have explored the use of alternative root filling materials other than GP. Among the classes of materials that are being explored as novel endodontic therapy platforms, nanodiamonds (NDs) may offer unique advantages due to their favorable properties, particularly for dental applications. These include versatile faceted surface chemistry, biocompatibility, and their role in improving mechanical properties, among others. This study developed a ND-embedded GP (NDGP) that was functionalized with amoxicillin, a broad-spectrum antibiotic commonly used for endodontic infection. Comprehensive materials characterization confirmed improved mechanical properties of NDGP over unmodified GP. In addition, digital radiography and microcomputed tomography imaging demonstrated that obturation of root canals with NDGP could be achieved using clinically relevant techniques. Furthermore, bacterial growth inhibition assays confirmed drug functionality of NDGP functionalized with amoxicillin. This study demonstrates a promising path toward NDGP implementation in future endodontic therapy for improved treatment outcomes.

Ultrananocrystalline diamond-CMOS device integration route for high acuity retinal prostheses.

High density electrodes are a new frontier for biomedical implants. Increasing the density and the number of electrodes used for the stimulation of retinal ganglion cells is one possible strategy for enhancing the quality of vision experienced by patients using retinal prostheses. The present work presents an integration strategy for a diamond based, high density, stimulating electrode array with a purpose built application specific integrated circuit (ASIC). The strategy is centered on flip-chip bonding of indium bumps to create high count and density vertical interconnects between the stimulator ASIC and an array of diamond neural stimulating electrodes. The use of polydimethylsiloxane (PDMS) housing prevents cross-contamination of the biocompatible diamond electrode with non-biocompatible materials, such as indium, used in the microfabrication process. Micro-imprint lithography allowed edge-to-edge micro-scale pattering of the indium bumps on non-coplanar substrates that have a form factor that can conform to body organs and thus are ideally suited for biomedical applications. Furthermore, micro-imprint lithography ensures the compatibility of lithography with the silicon ASIC and aluminum contact pads. Although this work focuses on 256 stimulating diamond electrode arrays with a pitch of 150 µm, the use of indium bump bonding technology and vertical interconnects facilitates implants with tens of thousands electrodes with a pitch as low as 10 µm, thus ensuring validity of the strategy for future high acuity retinal prostheses, and bionic implants in general.