Longitudinal in vivo cationic contrast-enhanced computed tomography classifies equine articular cartilage injury and repair.

Cationic contrast-enhanced computed tomography (CECT) capitalizes on increased contrast agent affinity to the charged proteoglycans in articular cartilage matrix to provide quantitative assessment of proteoglycan content with enhanced images. While high resolution microCT has demonstrated success, we investigate cationic CECT use in longitudinal in vivo imaging at clinical resolution. We hypothesize that repeated administration of CA4+ will have no adverse side effects or complications, and that sequential in vivo imaging assessments will distinguish articular cartilage repair tissue from early degenerative and healthy cartilage in critically sized chondral defects.

Radiolabeled Biodistribution of Expansile Nanoparticles: Intraperitoneal Administration Results in Tumor Specific Accumulation.

Nanoparticle biodistribution is an essential component to the success of nanoparticle-based drug delivery systems. Previous studies with fluorescently labeled expansile nanoparticles, or "eNPs", demonstrated a high specificity of eNPs to tumors that is achieved through a materials-based targeting strategy. However, fluorescent labeling techniques are primarily qualitative in nature and the gold-standard for quantitative evaluation of biodistribution is through radiolabeling.

Contrast-enhanced micro-computed tomography of compartment and time-dependent changes in femoral cartilage and subchondral plate in a murine model of osteoarthritis.

A lack of understanding of the mechanisms underlying osteoarthritis (OA) progression limits the development of effective long-term treatments. Quantitatively tracking spatiotemporal patterns of cartilage and bone degeneration is critical for assessment of more appropriately targeted OA therapies. In this study, we use contrast-enhanced micro-computed tomography (μCT) to establish a timeline of subchondral plate (SCP) and cartilage changes in the murine femur after destabilization of the medial meniscus (DMM).

Tantalum Oxide Nanoparticles for the Quantitative Contrast-Enhanced Computed Tomography of Human Cartilage: Assessment of Biochemical Composition and Biomechanics.

Nanoparticle-based contrast agents, when used in concert with imaging modalities such as computed tomography (CT), enhance the visualization of tissues and boundary interfaces. However, the ability to determine the physiological state of the tissue via the quantitative assessment of biochemical or biomechanical properties remains elusive. We report the synthesis and characterization of tantalum oxide (TaO) nanoparticle (NP) contrast agents for rapid, nondestructive, and quantitative contrast-enhanced computed tomography (CECT) to assess both the glycosaminoglycan (GAG) content and the biomechanical integrity of human metacarpal phalangeal joint (MCPJ) articular cartilage.

Influence of fixation on CA4+ contrast enhanced microCT of articular cartilage and subsequent feasibility for histological evaluation.

CA4+ is a novel cationic iodinated contrast agent utilized for contrast-enhanced microCT (CECT). In this study, we compared CA4+ CECT for cartilage quantification of unfixed and neutral buffered formalin (NBF)-fixed rabbit distal femur cartilage after 8-, 24- and 30-hours of contrast agent diffusion. The stability of CA4+ binding to cartilage after PBS soak and decalcification was also investigated by CECT.

Quantitative Evaluation of Equine Articular Cartilage Using Cationic Contrast-Enhanced Computed Tomography.

Objective: To investigate the diffusion trajectory of a cationic contrast medium (CA4+) into equine articular cartilage, and to assess normal and degenerative equine articular cartilage using cationic contrast-enhanced computed tomography (CECT).

Design: In the first experiment (Exp1), equine osteochondral specimens were serially imaged with cationic CECT to establish the diffusion time constant and time to reach equilibrium in healthy articular cartilage. In a separate experiment (Exp2), articular cartilage defects were created on the femoral trochlea (defect joint) in a juvenile horse, while the opposite joint was a sham-operated control.

Cationic contrast-enhanced computed tomography distinguishes between reparative, degenerative, and healthy equine articular cartilage.

Cationic contrast-enhanced computed tomography (CECT) is a quantitative imaging technique that characterizes articular cartilage, though its efficacy in differentiating repair tissue from other disease states is undetermined. We hypothesized that cationic CECT attenuation will distinguish between reparative, degenerative, and healthy equine articular cartilage and will reflect biochemical, mechanical, and histologic properties. Chondral defects were created in vivo on equine femoropatellar joint surfaces.

Recapitulating bone development through engineered mesenchymal condensations and mechanical cues for tissue regeneration.

Large bone defects cannot form a callus and exhibit high complication rates even with the best treatment strategies available. Tissue engineering approaches often use scaffolds designed to match the properties of mature bone. However, natural fracture healing is most efficient when it recapitulates development, forming bone via a cartilage intermediate (endochondral ossification).

Assessment of healthy trapeziometacarpal cartilage properties using indentation testing and contrast-enhanced computed tomography.

Background: The trapeziometacarpal joint is a common site for osteoarthritis development in the hand. When osteoarthritis is present, it results in significant functional disabilities due to the broad range of activities performed by this joint. However, our understanding of osteoarthritis initiation and progression at this joint is limited because of the current lack of knowledge regarding the properties and structure of the corresponding cartilage layers.

Cytidine- and guanosine-based nucleotide-lipids.

Hybrid nucleotide-lipids composed of a lipid covalently attached to purine and pyrimidine nucleobases exhibit supramolecular properties. The novel cytidine and guanosine derivatives are promising bioinspired materials, which can act as supramolecular gelators depending on both the nucleobase and the presence of salts. These supramolecular properties are of broad interest for biomedical applications.

Quantitative Dual Contrast CT Technique for Evaluation of Articular Cartilage Properties.

Impact injuries of cartilage may initiate post-traumatic degeneration, making early detection of injury imperative for timely surgical or pharmaceutical interventions. Cationic (positively-charged) CT contrast agents detect loss of cartilage proteoglycans (PGs) more sensitively than anionic (negatively-charged) or non-ionic (non-charged, i.e.

Synthesis and Preclinical Characterization of a Cationic Iodinated Imaging Contrast Agent (CA4+) and Its Use for Quantitative Computed Tomography of Ex Vivo Human Hip Cartilage.

Contrast agents that go beyond qualitative visualization and enable quantitative assessments of functional tissue performance represent the next generation of clinically useful imaging tools. An optimized and efficient large-scale synthesis of a cationic iodinated contrast agent (CA4+) is described for imaging articular cartilage. Contrast-enhanced CT (CECT) using CA4+ reveals significantly greater agent uptake of CA4+ in articular cartilage compared to that of similar anionic or nonionic agents, and CA4+ uptake follows Donnan equilibrium theory.

Accumulation of nanoparticles in "jellyfish" mucus: a bio-inspired route to decontamination of nano-waste.

The economic and societal impacts of nano-materials are enormous. However, releasing such materials in the environment could be detrimental to human health and the ecological biosphere. Here we demonstrate that gold and quantum dots nanoparticles bio-accumulate into mucus materials coming from natural species such as jellyfish.

Decontamination of nanoparticles from aqueous samples using supramolecular gels.

The growing use of nanomaterials and their associated risks necessitate the emergence of efficient decontamination systems. The main objective of this study is to develop a new prototype based on artificial supramolecular hydrogel capable of removing nanoparticle (NP) waste and nanomaterial by-products from aqueous suspensions. We demonstrate the high trapping efficacy of the low-molecular-weight gelators (LMWG) for very small particles (quantum dots (QDs), gold nanoparticles (AuNPs), TiO2 nanoparticles (TiO2-NPs), below 50 nm in diameter) from aqueous suspensions.

Glycosyl-Nucleolipids as new bioinspired amphiphiles.

Four new Glycosyl-NucleoLipid (GNL) analogs featuring either a single fluorocarbon or double hydrocarbon chains were synthesized in good yields from azido thymidine as starting material. Physicochemical studies (surface tension measurements, differential scanning calorimetry) indicate that hydroxybutanamide-based GNLs feature endothermic phase transition temperatures like the previously reported double chain glycerol-based GNLs. The second generation of GNFs featuring a free nucleobase reported here presents a better surface activity (lower glim) compared to the first generation of GNFs.

Tuning molecular interactions in lipid-oligonucleotides assemblies via locked nucleic acid (LNA)-based lipids.

Hybrid nucleotide-lipids containing locked nucleic acid (LNA) show enhanced hybridization properties with complementary single strand RNAs compared to DNA lipid analogues. The LNA adenosine lipid features unique binding properties with a high binding affinity for poly-uridine and the entropically driven formation of a stable complex (K(d) ≈ 43 nM). Enhanced hybridization properties of LNA-based lipids should be applicable for the development of oligonucleotide (ON) delivery systems or as small molecule binders to RNA for novel therapeutic strategies.

Quantum dot lipid oligonucleotide bioconjugates: toward a new anti-microRNA nanoplatform.

The construction of new nanotools is presented here using the example of fluorescent semiconductor nanocrystals, quantum dots (QDs). In this study, the implementation of the new lipid oligonucleotide conjugate-functionalized quantum dots (LON-QDs) is realized in four steps: (i) the synthesis of the lipid oligonucleotide conjugates (LONs), (ii) the encapsulation of QDs by nucleolipids and LONs, (iii) the study of the duplex formation of LON-QDs with the complementary ON partners, and (iv) the cellular uptake of the LON-QD platform and hybridization with the target ONs (microRNA and miR-21).

A thermosensitive low molecular weight hydrogel as scaffold for tissue engineering.

Hydrogels that are non-toxic, easy to use, cytocompatible, injectable and degradable are valuable biomaterials for tissue engineering and tissue repair. However, few compounds currently fulfil these requirements. In this study, we describe the biological properties of a new type of thermosensitive hydrogel based on low-molecular weight glycosyl-nucleosyl-fluorinated (GNF) compound.

Glycosylated nucleoside lipid promotes the liposome internalization in stem cells.

We report new glycosyl-nucleoside-lipid based liposomes decorated with sugar moieties. The GNL-liposomes feature a suitable glycosylated surface for their internalization into ADSC stem cells.

Hybrid lipid oligonucleotide conjugates: synthesis, self-assemblies and biomedical applications.

Hybrid lipid oligonucleotide conjugates are finding more and more biotechnological applications. This short critical review highlights their synthesis, supramolecular organization as well as their applications in the field of biotechnology (111 references).

Ferrocene-bis(thymine/uracil) conjugates: base pairing directed, spacer dependent self-assembly and supramolecular packing.

X-ray crystallographic studies of methylene linked Ferrocene-bis(thymine/uracil) conjugates Fc(T:T)(M) and Fc(U:U)(M) reveal base dependent 2-D supramolecular assemblies generated via wobble self-pairing for bis-thymine and reverse wobble self-pairing for bis-uracil conjugates, differing in architecture from the corresponding butylene spacer linked conjugates.

Ferrocene-linked thymine/uracil conjugates: base pairing directed self-assembly and supramolecular packing.

Ferrocene-linked bis(nucleobase) (1a-c) and chimeric nucleobase (1d) conjugates have been synthesized from mono- and bis(hydroxybutyl)ferrocene 6 via Mitsunobu reaction as the key step. X-ray crystallographic studies of ferrocene bis(nucleobase) conjugates reveal two-dimensional supramolecular organizations of backbones through self-assembled Watson-Crick and reverse Watson-Crick type pairs. Ferrocene-bis(thymine) conjugate self-assembles by reverse Watson-Crick pairing, while the corresponding bis(uracil) conjugate self-assembles by alternating WC and reverse WC type pairing.