ObjectiveTo summarize the recent progress of the controlled releasing delivery of biological factors for cartilage repair. MethodsThe recently published 1iterature at home and abroad on the controlled releasing delivery of biological factors for cartilage repair was reviewed and summarized. ResultsVarious biological factors have been applied for repairing cartilage. For better cartilage repair effects, controlled releasing delivery of biological factors can be applied by means of combining biological factors with degradable biomaterials, or by micro- and nano-particles. Meanwhile, multiple biologic delivery and temporally controlled delivery are also inevitable choices. ConclusionAlthough lots of unsolved problems exist, the controlled releasing delivery of biological factors has been a research focus for cartilage repair because of the controllability and delicacy.
Objective To investigate the physicochemicalproperties of the calcium phosphate cement (CPC) containing Danshen composite injection and its drug release rate. Methods This experiment included 4 groups and each group contained 6 specimens. CPC (2 g) was mixed with the setting solution that served as thecontrol group; 0.1,0.5 and 1.0 ml of Danshen composites injection (concentration, 1 000 mg/ml; pH, 7.35) were respectively added to CPC (2 g), which were used as the experimental groups 1, 2 and 3. The resulting specimens were investigated by the X-ray diffraction (XRD), the fourier transformed infrared spectroscopy(FTIR), and the scanning electron microscope (SEM).ResultsThe XRD analysis showed that the control group had a typical diffraction pattern of the hydroxypatite (HAP), which was consistent with the standard patternof HAP. When more Danshen was added in the experimental groups, the diffractionpeaks of HAP gradually decreased; when the diffraction angle 2θ was about 25.92°, the HAP peaks disappeared. Based on the FTIR analysis, with an increase of the drug concentration, the absorption peak of the hydroxy groups decreased. The SEM showed that the size of the CPC particle was related to the drug concentration; with an increase of the drug concentration, the CPC particle increased in number, resulting in an increasing trend of coacervation. The elution test showed that the drugrelease rate and capacity varied with the different concentrationsof Danshen. The initial release rate was relatively great, but after 96 hours the rate slowed down, lasting for a long time. Conclusion The physicochemical properties of CPC do not change when a proper dose (0.1 ml/2 g) of Danshen isadded to CPC. The Danshen composite can be effectively released from CPC, and so CPCcan be used as an ideal drugdelivery carrier for Danshen composite.
An clinical and pharmacokinetic study for a drug delivery system (DDS) of gentamycin-loaded chitosan bar were carried out with the purpose to evaluate its efficacy and giving further data for its clinical applications. Eighteen cases of chronic osteomyelitis were treated by surgical necrectomy with implantation of gentamycin-load chitosan bar in the prepared bone cavity. After operation, the concentration of gentamycin in serum and wound drainage fluid were examined at different times and blood urea nitrogen (BUN) and serum creatinine (Cr) as well. The clinical results were evaluated by the conditions of wound healing and clinical and roentgenographic manifestations. The results showed that the serum gentamycin concentration reached its peak level (0.86 microgram/ml) at 24 hours after operation and lasted for 4 days. No increase in the concentrations of BUN and Cr were observed after implantation. The gentamycin concentration in wound drainage fluid was several hundred times higher than the minimum inhibitory concentration (MIC) for staphylococcus aureus. All of the 18 cases were followed up for 24.8 months (in an range of 6-34 months) 16 patients received initial cure and without any recurrence. So, it could be concluded that the gentamycin-loaded chitosan DDS was a simple and effective method for the treatment of chronic osteomylitis without the necessity to carry out a second operation to remove the drug carrier, and it was sound to popularize its clinical application.
ObjectiveTo explore the related factors for the influences and outcomes of mothers and infants, and further provide a basic reference for reducing maternal and prenatal mortality caused by central placenta previa, through the analysis of its clinical characteristics. MethodsWe retrospectively analyzed the clinical data of 89 patients with central placenta previa treated from January to August 2012. ResultsThere were 89 patients with central placenta previa, and the average age of these patients was (29.6±11.4) years, and the average number of pregnancy among the patients was 3.17. Nine patients had scar uterus; 8 had pernicious placenta previa (9%); 34 had prenatal anemia symptoms; 44 had prenatal vaginal bleeding with the bleeding volume ranged from 2 to 500 mL; 40 were treated before delivery. The average gestational age was 36 weeks ±4.2 days, and 28 of them were readmitted. The intraoperative bleeding in such patients as had placenta located in the anterior wall, placenta adhesion or implantation, history of uterine cavity operation or multipara was more than other patients. The postpartum hemorrhage of patients with the gestational age of 36 weeks or more was more than that of patients with the gestational age shorter than 36 weeks. The incidence of fetal distress in patients with the gestational age of 36 weeks or more is lower and the neonatal 1-minute Apgar score was higher than that in patients with the gestational age shorter than 36 weeks (P<0.05). ConclusionThe treatment of central type of placenta previa should be more active to prolong the gestational week. Patients with placenta adhesion or implantation, caesarean, multipara and placenta in the anterior wall are susceptible to intraoperative bleeding during the termination of pregnancy. Termination of pregnancy in these patients with central placenta previa should be carried out by cesarean section when gestation is more than 36 weeks to reduce postpartum hemorrhage and complications.
The suprachoroidal space is a potential space between the sclera and choroid. Suprachoroidal spacedrug delivery is becoming an applicable method to the ocular posterior segment diseases. Because it targets the choroid, retinal pigment epithelium and retina with high bioavailability and safety, while maintaining low levels elsewhere in the eye. In recent years, new discoveries has been carried out in different areas of interest, such as drug delivery methods, pharmacokinetics and clinical trials. Clinical trials with suprachoroidal space injection of triamcinolone acetonide are executed with promising findings for patients with noninfectious uveitis and diabetic macular edema. Suprachoroidal space triamcinolone acetonide injectable suspension is the first and currently the only agent specifically approved for uveitic macular edema by Food and Drug Administration. Nowadays, many clinical trails with suprachoroidal space drug delivery have been explored, although there are still many risks and uncertainties. With the development of technology in the future, suprachoroidal space drug delivery appears to be a promising treatment modality for ocular posterior segment diseases.
Exosomes are nanoscale vectors with a diameter of 30~100 nm secreted by living cells, and they are important media for intercellular communication. Recent studies have demonstrated that exosomes can not only serve as biomarkers for diagnosis, but also have great potential as natural drug delivery vectors. Exosomes can be loaded with therapeutic cargos, including small molecules, proteins, and oligonucleotides. Meanwhile, the unique biological compatibility, high stability, and tumor targeting of exosomes make them attractive in future tumor therapy. Though exosomes can effectively deliver bioactive materials to receptor cells, there is a wide gap between our current understanding of exosomes and their application as ideal drug delivery systems. In this review, we will briefly introduce the function and composition of exosomes, and mainly summarize the potential advantages and challenges of exosomes as drug carriers. Finally, this review is expected to provide new ideas for the development of exosome-based drug delivery systems.
Objective To assessment of the echogenicity of the ultrasound-guided catheter and its associated delivery system. Methods The study consisted of in vitro characterization experiments and animal studies. In the in vitro phase, the acoustic and mechanical properties of the ultrasound-guided catheter were compared with those of the traditional MPA2 catheter, including parameters such as echo intensity, recognizability, and angle dependence. In the animal experiments, a ventricular septal defect (VSD) model was established in miniature pigs to compare the procedural performance of the ultrasound-guided delivery system versus the conventional system. Evaluation indicators included the time required for the system to cross the VSD, the detection rate of the system within the right ventricle, and the occurrence of intraoperative complications. Results The ultrasound-guided catheter demonstrated a significantly higher mean echo intensity than the MPA2 catheter[ (237.3±1.8) dB vs. (190.9±13.1) dB, P<0.001] and a markedly improved recognizability rate (82.3%±5.6% vs. 26.7±3.2%, P<0.001), along with better angle independence and image quality. In animal experiments, the ultrasound-guided delivery system significantly reduced the time required to cross the VSD (18.5±5.7 min vs. 30.3±4.5 min, P<0.001) and substantially increased the detection rate within the right ventricle (100% vs. 30%). No severe complications occurred in any experimental animal. Conclusion The ultrasound-guided catheter and its corresponding delivery system exhibited superior ultrasound visibility and operational performance in both in vitro and animal experiments, indicating strong potential for clinical application.
Microneedles have emerged as the new class of local drug delivery system that has broad potential for development. Considering that the microneedles can penetrate tissue barriers quickly, and provide localized and targeted drug delivery, their applications have gradually expanded to non-transdermal drug delivery recently, which are capable of providing rapid and effective treatment for injuries and diseases of organs or tissues. However, a literature search revealed that there is a lack of summaries of the latest developments in non-transdermal drug delivery research by using biomedical polymeric microneedles. The review first described the materials and fabrication methods for the polymeric microneedles, and then reviewed a representative application of microneedles for non-transdermal drug delivery, with the primary focus being on treating and repairing the tissues or organs such as oral cavity, ocular tissues, blood vessels and heart. At the end of the article, the opportunities and challenges associated with microneedles for non-transdermal drug delivery were discussed, along with its future development, in order to provide reference for researchers in the relevant field.
【Abstract】 Objective To introduce a new method using calcium phosphate cement/Danshen drug del ivery systemfor avascular necrosis of femoral head and to evaluate its cl inical outcome. Methods From May 2000 to June 2005, 48 patients (54 hips) with avascular necrosis of femoral head were treated with calcium phosphate cement/Danshen drug del ivery system implantation in the involved femoral head. There were 32 males(36 hips) and 16 females(18 hips) with an average age of 38.7 years (26-62 years). Twenty-one cases had the history of drinking or smoking, 15 cases had the history of receiving hormonotherapy and 2 had the history of injury in hip joint. The disease course was 2-32 months. According to standard of Association Research Circulation Osseous (ARCO) staging, 9 hips were classified as stage I, 31 as stage II and 14 as stage III. The operation consisted of removal of necrotic bone under weight-loading cartilage and the implantation of calcium phosphate cement/Danshen drug del ivery system, all mani pulations were done through a bone tunnel in trochanter. The function of hi p joint were evaluated and X-ray films were taken pre- and post-operatively. Results No phlebothrombosis of leg and foreign body action occurred in all cases, and incision healed by first intention. The postoperative follow-up averaged 42.5 months, ranging from 22 to 73 months. According to the evaluation criterion of Dandong 1995 for adult avascular necrosis of femoral head, the results were excellent in 33 hi ps, good in 17, fair in 3 and poor in 1, the excellent and good rate was92.6 %. Conclusion This method is relatively simple with less invasion, it not only improves the microcirculation of femoral head by local appl ication of traditional Chinese medicine, but also provide mechanic buttress in the weight-loaded area, which is beneficial to repair and reconstruction of femoral head. It may be a choice of minimally invasion surgery for femoral head necrosis.
摘要:眼部的局部給藥方式影響著藥物作用的強度,速率及持續時間和不良反應。視網膜,脈絡膜,玻璃體及視神經的疾病則對眼后節的局部給藥治療提出了挑戰,以局部給藥的方式通過解剖學的膜屏障及淚液排泄,并達到在特定部位起治療作用的藥物濃度是其中的重要課題。全身給藥則難以在眼組織積蓄足夠的藥物濃度,且易引起全身性的不良反應。眼表局部應用滴眼劑在淚液循環及角膜,結膜的屏障作用下易發生流失,而有創的給藥方式包括玻璃體內注射,結膜下注射等變得越來越普遍的同時,除對病人造成疼痛不適外,甚至也可導致多種嚴重于疾病本身的并發癥。本文綜述了近幾年來隨著各種眼科疾病分子機制的研究和解明,眼部局部給藥方式及新劑型的藥代動力學及安全性的研究進展。Abstract: The ocular drug delivery system affects the drug’s efficacy,rate of speed,velocity and adverse reaction.How to deliver the drug with therapeutic local concentrations to the posterior segment remains a challenge. Many invasive methods such as intravitreal injection,subconjunctival injection are generally used,noninvasive method like eye drop can not pass through the barrier of the eye although it is convenient.The recent progress in safty and pharmacokinetic of ocular drug delivery system is reviewed in this article.