scholarly journals Controlled SrR Delivery by the Incorporation of Mg Particles on Biodegradable PLA-Based Composites

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1061
Author(s):  
Ana Ferrández-Montero ◽  
Alvaro Eguiluz ◽  
Elena Vazquez ◽  
Joab David Guerrero ◽  
Zoilo Gonzalez ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Drug Delivery ◽  
Synergetic Effect ◽  
Halloysite Nanotubes ◽  
Vital Role ◽  
The Body ◽  
Mineral Density ◽  
Medium Ph ◽  
Inert Polymer

Among several ions playing a vital role in the body, Sr2+ and Mg2+ are involved in the mechanism of bone formation, making them especially useful for bone tissue engineering applications. Recently, polylactic acid (PLA)/Mg composites have emerged as a promising family of biomaterials due to their inherent biocompatibility and biodegradability properties. In these composites, polymer and bio-metal have a synergetic effect—while the PLA inhibits the Mg fast reactivity, Mg provides bioactivity to the inert polymer buffering the medium pH during degradation. Meanwhile, the typical form of administrating Sr2+ to patients is through the medication strontium ranelate (SrR), which increases the bone mineral density. Following this interesting research line, a new group of composites, which integrates Mg particles and SrR charged onto halloysite nanotubes (HNT) in a polymeric matrix, was proposed. PLA/Mg/SrR–HNT composites have been processed following a colloidal route, obtaining homogenous composites granulated and film-shaped. The drug delivery profile was evaluated in terms of in vitro lixiviation/dissolution paying special attention to the synergism of both ions release. The combination of two of the most reported ions involved in bone regeneration in the composite biomaterial may generate extra interest in bone healing applications.

Dissolution Medium Responsive Simvastatin Release from Biodegradable Apatite Cements Drug Delivery System - The Therapeutically Effect and their Histology in Osteoporosis Rats -

2011 ◽  
Vol 493-494 ◽  
pp. 684-688 ◽  
Author(s):  
Makoto Otsuka ◽  
Hideyuki Hamada ◽  
Kuniko Otsuka ◽  
Hiroyuki Ohshima
Keyword(s):  
Bone Mineral Density ◽  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery System ◽  
Bone Mineral ◽  
Delivery System ◽  
Dissolution Medium ◽  
Mineral Density ◽  
Apatite Cement

A biodegradable drug delivery system was established using an apatite cement containing simvastatin. The in-vitro drug release from apatite with lower-crystallinity was investigated under simulated osteoblast and osteoclast conditions (SOB and SOC). Apatite cement containing 6% simvastatin had lower crystallinity as the same as natural bone. In-vitro drug release tests were performed under SOB in simulated body fluid (pH 7.8), and then under SOC in acetate buffer (pH4.5) at 37.0｡C, and the process repeated twice. The device had lower drug release rates under SOB, but significantly higher rates under SOC. The simvastatin release rate was 15 times higher under SOC than SOB. The device showed dissolution medium responsive drug release. After implantation of the APC containing simvastatin in osteoporosis rats, the bone mineral density was evaluated by the X-ray computed tomography. The result indicated that the bone mineral density of APC implanted rat was significantly higher than that of control diseased.

scholarly journals Osteopontin Deficiency Induces Parathyroid Hormone Enhancement of Cortical Bone Formation

Endocrinology ◽  
2003 ◽  
Vol 144 (5) ◽  
pp. 2132-2140 ◽  
Author(s):  
Keiichiro Kitahara ◽  
Muneaki Ishijima ◽  
Susan R. Rittling ◽  
Kunikazu Tsuji ◽  
Hisashi Kurosawa ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Formation ◽  
Bone Mass ◽  
Cortical Bone ◽  
Cancellous Bone ◽  
Wild Type ◽  
Mineral Density ◽  
Cortical Bone Mass ◽  
Intermittent Pth

Intermittent PTH treatment increases cancellous bone mass in osteoporosis patients; however, it reveals diverse effects on cortical bone mass. Underlying molecular mechanisms for anabolic PTH actions are largely unknown. Because PTH regulates expression of osteopontin (OPN) in osteoblasts, OPN could be one of the targets of PTH in bone. Therefore, we examined the role of OPN in the PTH actions in bone. Intermittent PTH treatment neither altered whole long-bone bone mineral density nor changed cortical bone mass in wild-type 129 mice, although it enhanced cancellous bone volume as reported previously. In contrast, OPN deficiency induced PTH enhancement of whole-bone bone mineral density as well as cortical bone mass. Strikingly, although PTH suppressed periosteal bone formation rate (BFR) and mineral apposition rate (MAR) in cortical bone in wild type, OPN deficiency induced PTH activation of periosteal BFR and MAR. In cancellous bone, OPN deficiency further enhanced PTH increase in BFR and MAR. Analysis on the cellular bases for these phenomena indicated that OPN deficiency augmented PTH enhancement in the increase in mineralized nodule formation in vitro. OPN deficiency did not alter the levels of PTH enhancement of the excretion of deoxypyridinoline in urine, the osteoclast number in vivo, and tartrate-resistant acid phosphatase-positive cell development in vitro. These observations indicated that OPN deficiency specifically induces PTH activation of periosteal bone formation in the cortical bone envelope.

scholarly journals Applications of Nanomaterials for Theranostics of Melanoma

2020 ◽  
Vol 1 (1) ◽  
pp. 39-55
Author(s):  
Guanqiao Jin ◽  
Pohlee Cheah ◽  
Jing Qu ◽  
Lijuan Liu ◽  
Yongfeng Zhao
Keyword(s):  
Drug Delivery ◽  
Molecular Imaging ◽  
Early Diagnosis ◽  
Real Time ◽  
Treatment Plan ◽  
Chemotherapeutic Agents ◽  
The Body ◽  
Diagnostic Methods ◽  
Therapeutic Drug

Melanoma is an aggressive form of skin cancer with a very high mortality rate. Early diagnosis of the disease, the utilization of more potent pharmacological agents, and more effective drug delivery systems are essential to achieve an optimal treatment plan. The applications of nanotechnology to improve therapeutic efficacy and early diagnosis for melanoma treatment have received great interest among researchers and clinicians. In this review, we summarize the recent progress of utilizing various nanomaterials for theranostics of melanoma. The key importance of using nanomaterials for theranostics of melanoma is to improve efficacy and reduce side effects, ensuring safe implementation in clinical use. As opposed to conventional in vitro diagnostic methods, in vivo medical imaging technologies have the advantages of being a type of non-invasive, real-time monitoring. Several common nanoparticles, including ultrasmall superparamagnetic iron oxide nanoparticles, silica nanoparticles, and carbon-based nanoparticles, have been applied to deliver chemotherapeutic agents for the theranostics of melanoma. The application of nanomaterials for theranostics in molecular imaging (MRI, PET, US, OI, etc.) plays an important role in targeting drug delivery of melanoma, by monitoring the distribution site of the molecular imaging probe and the therapeutic drug in the body in real-time. Hence, it is worthwhile to anticipate the approval of these nanomaterials for theranostics in molecular imaging by the US Food and Drug Administration in clinical trials.

Accelerated Aging: The Role of Socioeconomic, Social, Demographic, and Biological Factors on Bone Mineral Density

2018 ◽  
Vol 41 (5) ◽  
pp. 443-466 ◽  
Author(s):  
Margaret Gough ◽  
Kanya Godde
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Accelerated Aging ◽  
Well Being ◽  
The United States ◽  
The Body ◽  
Mineral Density ◽  
Reactive Protein ◽  
Biological Variables ◽  
Social Demographic

We investigate socioeconomic, social, demographic, and biological variables that are associated with chronic stress in the body to assess whether they have an effect on bone mineral density (BMD) as an indicator of accelerated aging. Multiple regression models were derived from data in the Midlife in the United States: A National Longitudinal Study of Health and Well-Being, Waves 1 (1995–1996) and 2 (2004–2006). Three BMD variables were used as outcomes: femoral, femoral neck, and spine T scores. The sample included 333 men and women aged 34–80. Poverty and C-reactive protein were related to BMD for spine T scores, partially consistent with hypotheses. But, marital status, perceived support of a partner, and education were not associated. Friend strain was discovered to have a relationship with BMD. More variables, and from a broader context, need to be examined together to understand what affects reduced BMD, given the high costs of accelerated aging.

In Vitro and in Vivo Spiral CT to Determine Bone Mineral Density: Initial Experience in Patients at Risk for Osteoporosis

Radiology ◽  
2004 ◽  
Vol 231 (3) ◽  
pp. 805-811 ◽  
Author(s):  
Thomas M. Link ◽  
Boris B. Koppers ◽  
Thomas Licht ◽  
Jan Bauer ◽  
Ying Lu ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
At Risk ◽  
Bone Mineral ◽  
Spiral Ct ◽  
Initial Experience ◽  
Mineral Density ◽  
Patients At Risk

Assessment of the strength of proximal femur in vitro: Relationship to femoral bone mineral density and femoral geometry

Bone ◽  
1997 ◽  
Vol 20 (3) ◽  
pp. 213-218 ◽  
Author(s):  
X.G. Cheng ◽  
G. Lowet ◽  
S. Boonen ◽  
P.H.F. Nicholson ◽  
P. Brys ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Proximal Femur ◽  
Femoral Bone ◽  
Mineral Density ◽  
Femoral Bone Mineral Density ◽  
Femoral Geometry

NANOMEDICINES: DELIVERING DRUGS USING BOTTOM UP NANOTECHNOLOGY

2005 ◽  
Vol 04 (05n06) ◽  
pp. 855-861 ◽  
Author(s):  
MARTIN GARNETT
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Biodegradable Polymers ◽  
Drug Loading ◽  
Dna Delivery ◽  
Delivery Systems ◽  
The Body ◽  
Nanosized Materials

The use of nanosized materials changes the way in which drugs are handled by the body and offers opportunities to improve drug delivery. The physiological mechanisms controlling the distribution of nanosized materials (enhanced permeability and retention effect, cellular uptake pathways and opsonisation/elimination of nanoparticles) are described. Two different nanosized drug delivery systems are considered; drug delivery and DNA delivery. The deficiencies of currently available biodegradable polymers for preparation of drug containing nanoparticles are mainly the amount of drug that can be incorporated and the rapid rate of drug release. The development of new biodegradable polymers which can interact with the drug and so significantly increase drug loading and decrease the rate of drug release are outlined. DNA delivery necessitates overcoming a variety of biological barriers. We are developing polyelectrolyte complexes of DNA with cationic polyamidoamines (PAA) as a delivery system. Complexing PAA with DNA results in good transfection of cells in vitro. However, in vivo, a more complex arrangement of PAA, Polyethylene glycol-PAA copolymers, DNA and the use of ligands will be required. Despite these efforts, further developments will be needed in nanotechnology for both drug and DNA nanoparticle delivery systems to achieve our clinical objectives.

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