Multifunctional drug delivery system using starch-alginate beads for controlled release

Utilizing starch-containing alginate beads, a novel drug delivery system (DDS) was developed. With the starch inside, the composite bead could be dried in its original bead shape and handled in the dried state. By employing alginate multi-coating strategy on the starch-alginate beads, detained or controlled release was efficiently achieved and successfully demonstrated for a model peptide drug, L-phenylalanine. The initial latent time and release rate of the drug inside the beads were able to be controlled simply by varying the number of multi-coatings. While the latent time for the initial release was negligible for non-coated starch-alginate beads, the latent times of beads coated one, two, and four times increased to 15, 30, and 70 min, respectively. Furthermore, the alginate component of the composite beads could adsorb and remove heavy metals such as lead from the body. These multifunctional beads combined with the novel coating process will greatly benefit alginate gel-based DDS.     

Os acromiale: evaluation and treatment

Os acromiale is a developmental aberration in which the distal acromion fails to fuse. This aberration is often discovered incidentally but may present with a clinical picture similar to that of subacromial impingement syndrome. Treatment for symptomatic os acromiale is initially nonoperative-activity modification, physical therapy, corticosteroid injection, use of nonsteroidal anti-inflammatory medication. Nonoperative management of clinically significant, radiographically confirmed os acromiale should be pursued for at least 6 months before consideration of surgical intervention. Subacromial decompression is often necessary to address symptoms of impingement. Excision of the os fragment may provide definitive treatment for smaller fragments (<3 cm). Removal of larger fragments remains controversial and should be approached with caution. Surgical fixation of larger fragments with or without supplemental autograft in conjunction with a structured postoperative program of physical therapy can reliably provide relief for symptomatic os acromiale.     

Complications of tissue expansion in a public hospital

Avoidance of complications in tissue expansion requires careful outpatient observation and consistent follow-up-two factors that are difficult to manage in a city hospital-based population. To determine the complication rate of tissue expanders in a given population, the authors reviewed retrospectively 34 tissue expanders placed in 30 patients at a New York City public hospital over a 7-year period from 1989 to 1996. The mean age of the patients at the time of insertion was 25 years (range, 11 months-65 years). The most common conditions for treatment were nevi (N = 11), burn scars (N = 8), breast reconstructions (N = 8), and spina bifida (N = 4). Complications occurred in 22 of 34 expanders (65%). Complications included deep infection (N = 11), exposure (N = 7), breakdown of the surgical wound (N = 4), cellulitis (N = 3), drainage (N = 1), and deflation (N = 1). Major complications resulted in premature removal in 13 of 34 expanders (38%). Minor complications leading to successful completion of the expansion process occurred with 9 of 34 expanders (27%). No complications were recorded in the remaining 12 of 34 expanders (35%). Although tissue expansion is a potentially safe and effective method of reconstruction, this review should alert the surgeon to the distinct challenges that may be encountered in the public hospital.     

Advances in Targeted Drug Delivery Approaches for the Central Nervous System Tumors: The Inspiration of Nanobiotechnology

At present, brain tumor is among the most challenging diseases to treat and the therapy is limited by the lack of effective methods to deliver anticancer agents across the blood-brain barrier (BBB). BBB is a selective barrier that separates the circulating blood from the brain extracellular fluid. In its neuroprotective function, BBB prevents the entry of toxins, as well as most of anticancer agents and is the main impediment for brain targeted drug delivery approaches. Nanotechnology-based delivery systems provide an attractive strategy to cross the BBB and reach the central nervous system (CNS). The incorporation of anticancer agents in various nanovehicles facilitates their delivery across the BBB. Moreover, a more powerful tool in brain tumor therapy has relied surface modifications of nanovehicles with specific ligands that can promote their passage through the BBB and favor the accumulation of the drug in CNS tumors. This review describes the physiological and anatomical features of the brain tumor and the BBB, and summarizes the recent advanced approaches to deliver anticancer drugs into brain tumor using nanobiotechnology-based drug carrier systems. The role of specific ligands in the design of functionalized nanovehicles for targeted delivery to brain tumor is reviewed. The current trends and future approaches in the CNS delivery of therapeutic molecules to tumors are also discussed.     

Effects of a multilamellar emulsion on glucocorticoid-induced epidermal atrophy and barrier impairment

Skin atrophy is one of the most frequent side-effects of the topical glucocorticoid. Skin barrier impairment has also been reported as a steroid-induced side effect. Although there have been various studies on preventing or minimizing this atrophogenic effect, little has been reported about preventing barrier impairment. This study was performed to determine the effects of a multilamellar emulsion (MLE) that had a well-ordered lamellar structure on the steroid-induced barrier impairment and epidermal atrophy. To confirm these effects of MLE, 0.05% clobetasol-17-propionate (CP) and 0.05% clobetasol-17-propionate in MLE (MLE/CP) were topically applied to both flanks of hairless mice for 9 days. The topically applied CP induced a significant impairment of the epidermal permeability barrier, and MLE/CP also did not have a preventive effect on this change. However, skinfold thickness studies and histological studies showed that MLE/CP significantly reduced the steroid-induced atrophy. The topical application of MLE/CP was also shown to have a preventive effect on the steroid-induced increase of the stratum corneum (SC) surface pH. In addition, the electron microscopic findings showed relatively well-conserved lamellar bilayers in the skin treated with MLE, as compared to CP only. The results showed that the topical application of MLE immediately after CP treatment prevented the glucocorticoid-induced transepidermal water loss values increase. Light microscopy measurements showed that the skin treated with MLE immediately after CP treatment for 1 week had a slightly lower decline of skin thickness than did the CP-treated skin. These results suggest that MLE should be effective for preventing glucocorticoid-induced epidermal atrophy and for repairing the barrier impairment.     

Syringo-Subarachnoid-Peritoneal Shunt Using T-Tube for Treatment of Post-Traumatic Syringomyelia

Various surgical procedures for the treatment of post-traumatic syringomyelia have been introduced recently, but most surgical strategies have been unreliable. We introduce the concept and technique of a new shunting procedure, syringo-subarachnoid-peritoneal shunt. A 54-year-old patient presented to our hospital with a progressive impairment of motion and position sense on the right side. Sixteen years before this admission, he had been treated by decompressive laminectomy for a burst fracture of L1. On his recent admission, magnetic resonance (MR) imaging studies of the whole spine revealed the presence of a huge syrinx extending from the medulla to the L1 vertebral level. We performed a syringo-subarachnoid-peritoneal shunt, including insertion of a T-tube into the syrinx, subarachnoid space and peritoneal cavity. Clinical manifestations and radiological findings improved after the operation. The syringo-subarachnoid-peritoneal shunt has several advantages. First, fluid can communicate freely between the syrinx, the subarachnoid space, and the peritoneal cavity. Secondly, we can prevent shunt catheter from migrating because dural anchoring of the T-tube is easy. Finally, we can perform shunt revision easily, because only one arm of the T-tube is inserted into the intraspinal syringx cavity. We think that this procedure is the most beneficial method among the various shunting procedures.     

What have we learned from LCS mobile-bearing knee system?

Three hundred and sixty-four low contact stress (LCS) total knee arthroplasties that could be followed up for more than 5 years were clinically and radiographically analyzed. The median postoperative Hospital for Special Surgery score improved from 56 (range 32–77) to 91 (range 64–100) points, but median range of motion did not change from 120° (range 50°–135°) to 120° (range 85°–135°). Complications occurred in 16 cases (4%), and included postoperative polyethylene dislocation and intraoperative tibial condylar fracture, while five knees (1%) required revision surgery due to mechanical reasons. The overall prosthesis survival rate was 91% at 12 years. Although the LCS mobile-bearing knee system has theoretical advantages in terms of wear and loosening, the problem of polyethylene dislocation, intraoperative tibial fracture, and radiolucent lines should be solved for long survival. The clinical relevance of this study is that the LCS system provided good clinical and survival results.