Medicine and Health Sciences Commons^™

Physiological Roles Of Mammalian Transmembrane Adenylyl Cyclase Isoforms, Katrina F. Ostrom, Justin E. Lavigne, Tarsis F. Brust, Roland Seifert, Carmen Dessauer, Val J. Watts, Rennolds S. Ostrom

Pharmacy Faculty Articles and Research

Adenylyl cyclases (ACs) catalyze the conversion of ATP to the ubiquitous second messenger cAMP. Mammals possess nine isoforms of transmembrane ACs, dubbed AC1-9, that serve as major effector enzymes of G protein-coupled receptors. The transmembrane ACs display varying expression patterns across tissues, giving potential for them having a wide array of physiologic roles. Cells express multiple AC isoforms, implying that ACs have redundant functions. Furthermore, all transmembrane ACs are activated by Gα_s so it was long assumed that all ACs are activated by Gα_s-coupled GPCRs. AC isoforms partition to different microdomains of the plasma membrane and form …

Purification And Characterization Of A Nonspecific Lipid Transfer Protein 1 (Nsltp1) From Ajwain (Trachyspermum Ammi) Seeds, Meshal Nazeer, Humera Waheed, Maria Saeed, Saman Yousuf Ali, M. Iqbal Choudhary, Zaheer Ul-Haq, Aftab Ahmed

Pharmacy Faculty Articles and Research

Ajwain (Trachyspermum ammi) belongs to the family Umbelliferae, is commonly used in traditional, and folk medicine due to its carminative, stimulant, antiseptic, diuretic, antihypertensive, and hepatoprotective activities. Non-specific lipid transfer proteins (nsLTPs) reported from various plants are known to be involved in transferring lipids between membranes and in plants defense response. Here, we describe the complete primary structure of a monomeric non-specific lipid transfer protein 1 (nsLTP1), with molecular weight of 9.66 kDa, from ajwain seeds. The nsLTP1 has been purified by combination of chromatographic techniques, and further characterized by mass spectrometry, and Edman degradation. The ajwain nsLTP1 …

Simultaneous Bactericidal And Osteogenic Effect Of Nanoparticulate Calcium Phosphate Powders Loaded With Clindamycin On Osteoblasts Infected With Staphylococcus Aureus, Vuk Uskoković, Tejal A. Dasai

Pharmacy Faculty Articles and Research

S aureus internalized by bone cells and shielded from the immune system provides a reservoir of bacteria in recurring osteomyelitis. Its targeting by the antibiotic therapy may thus be more relevant for treating chronic bone infection than eliminating only the pathogens colonizing the bone matrix. Assessed was the combined osteogenic and antibacterial effect of clindamycinloaded calcium phosphate nanoparticles of different monophasic compositions on co-cultures comprising osteoblasts infected with S aureus. Antibiotic-carrying particles were internalized by osteoblasts and minimized the concentration of intracellular bacteria. In vitro treatments of the infected cells, however, could not prevent cell necrosis due to the …

Nanoparticles Of Cobalt-Substituted Hydroxyapatite In Regeneration Of Mandibular Osteoporotic Bones, Nenad Ignjatović, Zorica Ajduković, Vojin Savić, Stevo Najman, Dragan Mihailović, Perica Vasilijević, Zoran Stojanović, Vuk Uskoković, Dragab Uskoković

Pharmacy Faculty Articles and Research

Indications exist that paramagnetic calcium phosphates may be able to promote regeneration of bone faster than their regular, diamagnetic counterparts. In this study, analyzed was the influence of paramagnetic cobalt-substituted hydroxyapatite nanoparticles on osteoporotic alveolar bone regeneration in rats. Simultaneously, biocompatibility of the material was tested in vitro, on osteoblastic MC3T3-E1 and epithelial Caco-2 cells in culture. The material was shown to be biocompatible and nontoxic when added to epithelial monolayers in vitro, while it caused a substantial decrease in the cell viability as well as deformation of the cytoskeleton and cell morphology when incubated with the osteoblastic …

Phase Composition Control Of Calcium Phosphate Nanoparticles For Tunable Drug Delivery Kinetics And Treatment Of Osteomyelitis. Part 2: Antibacterial And Osteoblastic Response, Vuk Uskoković, Tejal A. Dasai

Pharmacy Faculty Articles and Research

Osteomyelitis has been traditionally treated by the combination of long-term antibiotic therapies and surgical removal of diseased tissue. The multifunctional material was developed in this study with the aim to improve this therapeutic approach by: (a) enabling locally delivered and sustained release of antibiotics at a tunable rate, so as to eliminate the need for repetitive administration of systemically distributed antibiotics; and (b) controllably dissolving itself, so as to promote natural remineralization of the portion of bone lost to disease. We report hereby on the effect of the previously synthesized calcium phosphates (CAPs) with tunable solubilities and drug release time …

Osteogenic And Antimicrobial Nanoparticulate Calcium Phosphate And Poly-(D, L-Lactide-Co-Glycolide) Powders For The Treatment Of Osteomyelitis, Vuk Uskoković, Charles Hoover, Marija Vukomanović, Dragan P. Uskoković, Tejal A. Dasai, Charles Hoover, Marija Vukomanović, Dragan P. Uskoković, Tejal A. Dasai

Pharmacy Faculty Articles and Research

Development of a material for simultaneous sustained and localized delivery of antibiotics and induction of spontaneous regeneration of hard tissues affected by osteomyelitis stands for an important clinical need. In this work, a comparative analysis of the bacterial and osteoblastic cell response to two different nanoparticulate carriers of clindamycin, an antibiotic commonly prescribed in the treatment of bone infection, one composed of calcium phosphate and the other comprising poly-(D,L-lactide-co-glycolide)-coated calcium phosphate, was carried out. Three different non-cytotoxic phases of calcium phosphate, exhibiting dissolution and drug release profiles in the range of one week to two months to one year, respectively, …

Revisiting The Fundamentals In The Design And Control Of Nanoparticulate Colloids In The Frame Of Soft Chemistry, Vuk Uskoković

Pharmacy Faculty Articles and Research

This review presents thoughts on some of the fundamental features of conceptual models applied in the design of fine particles in the frames of colloid and soft chemistry. A special emphasis is placed on the limitations of these models, an acknowledgment of which is vital in improving their intricacy and effectiveness in predicting the outcomes of the corresponding experimental settings. Thermodynamics of self-assembly phenomena illustrated on the examples of protein assembly and micellization is analyzed in relation to the previously elaborated thesis that each self-assembly in reality presents a co-assembly, since it implies a mutual reorganization of the assembling system …

Hydrolysis Of Amelogenin By Matrix Metalloprotease-20 Accelerates Mineralization In Vitro, Vuk Uskoković, Feroz Khan, Haichuan Liu, Halina Ewa Witkowska, Li Zhu, Wu Li, Stefan Habelitz

Pharmacy Faculty Articles and Research

In the following respects, tooth enamel is a unique tissue in the mammalian body: (a) it is the most mineralized and hardest tissue in it comprising up to 95 wt% of apatite; (b) its microstructure is dominated by parallel rods composed of bundles of 40 – 60 nm wide apatite crystals with aspect ratios reaching up to 1:10,000 and (c) not only does the protein matrix that gives rise to enamel guides the crystal growth, but it also conducts its own degradation and removal in parallel. Hence, when mimicking the process of amelogenesis in vitro, crystal growth has to …

Biomimetic Precipitation Of Uniaxially Grown Calcium Phosphate Crystals From Full-Length Human Amelogenin Sols, Vuk Uskoković, Wu Li, Stefan Habelitz

Pharmacy Faculty Articles and Research

Human dental enamel forms over a period of 2 – 4 years by substituting the enamel matrix, a protein gel mostly composed of a single protein, amelogenin with fibrous apatite nanocrystals. Self-assembly of a dense amelogenin matrix is presumed to direct the growth of apatite fibers and their organization into bundles that eventually comprise the mature enamel, the hardest tissue in the mammalian body. This work aims to establish the physicochemical and biochemical conditions for the synthesis of fibrous apatite crystals under the control of a recombinant fulllength human amelogenin matrix in combination with a programmable titration system. The growth …

Altered Self-Assembly And Apatite Binding Of Amelogenin Induced By N-Terminal Proline Mutation, Li Zhu, Vuk Uskoković, Thuan Le, Pamela Denbesten, Yulei Huang, Stefan Habelitz, Wu Li

Pharmacy Faculty Articles and Research

Objective—A single Pro-70 to Thr (p.P70T) mutation of amelogenin is known to result in hypomineralized amelogenesis imperfecta (AI). This study aims to test the hypothesis that the given mutation affects the self-assembly of amelogenin molecules and impairs their ability to conduct the growth of apatite crystals.

Design—Recombinant human full-length wild-type (rh174) and p.P70T mutated amelogenins were analyzed using dynamic light scattering (DLS), protein quantification assay and atomic force microscopy (AFM) before and after the binding of amelogenins to hydroxyapatite crystals. The crystal growth modulated by both amelogenins in a dynamic titration system was observed using AFM.

Results—As …

Prospects And Pits On The Path Of Biomimetics: The Case Of Tooth Enamel, Vuk Uskoković

Pharmacy Faculty Articles and Research

This review presents a discourse on challenges in understanding and imitating the process of amelogenesis in vitro on the molecular scale. In light of the analysis of imitation of the growth of dental enamel, it also impends on the prospects and potential drawbacks of the biomimetic approach in general. As the formation of enamel proceeds with the protein matrix guiding the crystal growth, while at the same time conducting its own degradation and removal, it is argued that three aspects of amelogenesis need to be induced in parallel: a) crystal growth; b) protein assembly; c) proteolytic degradation. A particular emphasis …

Enzymatic Processing Of Amelogenin During Continuous Crystallization Of Apatite, Vuk Uskoković, M.-K. Kim, W. Li, S. Habelitz

Pharmacy Faculty Articles and Research

Dental enamel forms through a protein-controlled mineralization and enzymatic degradation with a nanoscale precision that new engineering technologies may be able to mimic. Recombinant fulllength human amelogenin (rH174) and a matrix-metalloprotease (MMP-20) were employed in a pHstat titration system that enabled a continuous supply of calcium and phosphate ions over several days, mimicking the initial stages of matrix processing and crystallization in enamel in-vitro. Effects on the self-assembly and crystal growth from a saturated aqueous solution containing 0.4 mg/ml rH174 and MMP-20 with the weight ratio of 1:1000 with respect to rH174 were investigated. A transition from nanospheres to fibrous …