Jan Havlik

Boosting nanodiamond fluorescence: towards development of brighter probes

A novel approach for preparation of ultra-bright fluorescent nanodiamonds (fNDs) was developed and the thermal and kinetic optimum of NV center formation was identified. Combined with a new oxidation method, this approach enabled preparation of particles that were roughly one order of magnitude brighter than particles prepared with commonly used procedures.

Long-term results in patients with Lyme arthritis following treatment with ceftriaxone

A total of 35 patients with late stage Lyme borreliosis with involvement of the joints was followed up until 3 years after a 14 day course of 2 g ceftriaxone once daily i.v. Diagnosis was confirmed by indirect and direct microbiological methods as well as clinical signs and symptoms. Long term clinical results in 26 patients at 36 months were complete response or marked improvement in 19, relapse in six and new manifestations in four of the cases, respectively. Possible mechanisms for non-responding to therapy are discussed. Therapy was well tolerated; in no case discontinuation of treatment was necessary due to adverse drug reactions. The treatment results in this group of 35 patients with Lyme arthritis are considered successful. The data obtained are consistent with expectations based on the published experiences with ceftriaxone in this indication.SummaryA total of 35 patients with late stage Lyme borreliosis with involvement of the joints was followed up until 3 years after a 14 day course of 2 g ceftriaxone once daily i.v. Diagnosis was confirmed by indirect and direct microbiological methods as well as clinical signs and symptoms. Long term clinical results in 26 patients at 36 months were complete response or marked improvement in 19, relapse in six and new manifestations in four of the cases, respectively. Possible mechanisms for non-responding to therapy are discussed. Therapy was well tolerated; in no case discontinuation of treatment was necessary due to adverse drug reactions. The treatment results in this group of 35 patients with Lyme arthritis are considered successful. The data obtained are consistent with expectations based on the published experiences with ceftriaxone in this indication.Zusammenfassung35 Patienten mit Lyme-Borreliose im Spätstadium mit Gelenkbeteiligung wurden bis zu 3 Jahre nach einer 14tägigen Behandlung mit 2 g Ceftriaxon einmal täglich i.v. nachbeobachtet. Die Diagnose wurde durch direkte und indirekte mikrobiologische Nachweisverfahren sowie durch klinische Symptome gesichert. Nach 36 Monaten hatten von 26 auswertbaren Patienten 19 eine Heilung oder erhebliche Besserung erreicht, in sechs Fällen kam es zum Rezidiv und in einem Fall traten neue Manifestationen auf. Die möglichen pathogenetischen Vorgänge, die für das Therapieversagen verantwortlich sein könnten, werden diskutiert. Die Behandlung wurde gut vertragen. In keinem Fall zwangen Nebenwirkungen zum Absetzen der Therapie. Die Behandlung bei diesen 35 Patienten wird als erfolgreich beurteilt. Die Daten entsprechen Erfahrungen aus publizierten Studien mit Ceftriaxon bei dieser Indikation.

Plasmonic Nanodiamonds – Targeted Core-shell Type Nanoparticles for Cancer Cell Thermoablation

Targeted biocompatible nanostructures with controlled plasmonic and morphological parameters are promising materials for cancer treatment based on selective thermal ablation of cells. Here, core-shell plasmonic nanodiamonds consisting of a silica-encapsulated diamond nanocrystal coated in a gold shell are designed and synthesized. The architecture of particles is analyzed and confirmed in detail using electron tomography. The particles are biocompatibilized using a PEG polymer terminated with bioorthogonally reactive alkyne groups. Azide-modified transferrin is attached to these particles, and their high colloidal stability and successful targeting to cancer cells overexpressing the transferrin receptor are demonstrated. The particles are nontoxic to the cells and they are readily internalized upon binding to the transferrin receptor. The high plasmonic cross section of the particles in the near-infrared region is utilized to quantitatively ablate the cancer cells with a short, one-minute irradiation by a pulse 750-nm laser.

Ceftriaxone in the treatment of Lyme neuroborreliosis.

SummaryIn an open non-comparative clinical trial with the aim of evaluating the clinical efficacy and safety of a 14 day course of 2 g ceftriaxone once daily, 46 patients with neuroborreliosis were entered at the Infectious Diseases Teaching Hospital in Prague 8. In 39 patients the diagnosis was early Lyme neuroborreliosis. Seven patients suffered from late stage disease. Clinical results were 30% of patients cured at the end of treatment and 85% after 9 months in early stage disease. In late stage disease two patients out of seven were cured and four had improved after 12 months. One patient died because of cardiac infarction. In no patient had treatment to be discontinued because of adverse reactions to antibiotics.ZusammenfassungDie klinische Wirksamkeit und Sicherheit einer 14tägigen Therapie mit 2 g Ceftriaxon einmal täglich wurde bei 46 Patienten mit Neuroborreliose in einer offenen klinischen Studie bestimmt. Die Patienten wurden an dem Lehrkrankenhaus für Infektionskrankheiten in Prag 8 behandelt. Bei 39 Patienten bestand die Diagnose einer frühen Neuroborreliose. Sieben Patienten wiesen ein Spätstadium der Erkrankung auf. Am Ende der Therapiephase waren 30% der Patienten geheilt. Nach 9 Monaten bestand bei 85% der Patienten mit der Frühform der Neuroborreliose Symptomfreiheit, von den Patienten mit Neuroborreliose im Spätstadium waren zwei von sieben geheilt und vier hatten sich nach 12 Monaten gebessert. Ein Patient verstarb am Herzinfarkt. Ein Absetzen der Therapie wegen Nebenwirkungen war bei keinem der Patienten nötig.

Nanodiamonds as Intracellular Probes for Imaging in Biology and Medicine

In recent years, diamond nanoparticles have received a great deal of attention due to their unique photophysical and biological properties. Nanodiamonds (NDs) show low toxicity and are considered to be a highly biocompatible carbon nanomaterial useful in a wide range of applications. Thanks to their ability to accommodate nitrogen-vacancy (N-V) color centers, NDs are a prime example of non-photobleachable fluorescent labels and nanosensors. Here, we present a survey of ND applications in biology and medicine with an emphasis on bio-imaging. We focus on distinguishing the properties of detonation NDs and high-pressure high-temperature (HPHT) NDs and describing their physicochemical properties, structure and possible modifications by small molecules and biomolecules. We summarize and critically evaluate in vitro and in vivo data on ND toxicity and biocompatibility, cellular internalization, localization and targeting by surface-attached ligands. We discuss current achievements in bioimaging using fluorescent NDs and the potential of NDs in diagnostics and drug delivery.

Nanodiamonds: Behavior in Biological Systems and Emerging Bioapplications

In the past decade, nanodiamonds (NDs) have been recognized as a promising nanomaterial for bioapplications such as bioimaging and drug delivery in nanoscale medicine. Here, we present a comprehensive survey of current research on ND interactions with biological systems, including their biocompatibility, cellular internalization, localization, and targeting by surface-attached ligands. We critically assess the differences between different types of NDs, such as detonation NDs and high-pressure high-temperature (HPHT) NDs. We describe NDs’ physicochemical properties, structure, and available synthetic modifications by small molecules and biomolecules. Finally, we discuss emerging medical applications and bioapplications of these low-toxicity carbon nanoparticles.

Nanodiamonds embedded in shells

Abstract Novel nanomaterials based on nanodiamonds embedded in various types of shells are described. Numerous examples are presented to illustrate the general concept of conversion of the nanodiamond surface to fundamentally different nanointerfaces. Synthetic approaches leading to silica, polymer, protein, metal, and sp2 carbon-coated core–shell structures with a diamond core are discussed. The colloidal properties, prevention of aggregation, antifouling properties, shapes, and optical and material properties of the nanomaterials are presented, as well as their emerging applications.