Efficacy of antibiotic prophylaxis for reducing capsular contracture in prosthesis-based breast surgery: a systemic review and meta-analysis.

Antibiotics Prophylaxis to prevent capsular contracture in prosthesis-based breast surgery is common in clinical practice. However, there is currently a dearth of high-quality evidence concerning the effectiveness of antibiotic usage in this field. To identify all pertinent studies prior to January 2023, a comprehensive literature search was conducted in the PubMed, Embase, Web of Science, Cochrane Library, and Medline databases. The extracted data was then subjected to meta-analysis. Fourteen studies were retained in the analysis. According to the results, perioperative antibiotic prophylaxis did not reduce the risk of capsular contracture (RR 1.15, 95% CI 0.82-1.59, p = 0.55) or surgical-site infection (RD 0.01, 95% CI - 0.01 to 0.03, p = 0.59) compared to nonantibiotic prophylaxis. There was no statistically significant difference between extended antibiotic prophylaxis and perioperative antibiotic prophylaxis in terms of preventing capsular contracture, whether calculated by patient numbers (RD 0.01, 95% CI - 0.01 to 0.02, p = 0.87) or by total procedures (RD 0.00, 95% CI - 0.00 to 0.01, p = 0.88), or controlling surgical-site infection (RR 1.05, 95% CI 0.77-1.44, p = 0.27). Additionally, topical antibiotic irrigation did not decrease the risk of infection (RR 0.61, 95% CI 0.34-1.08, p = 0.29) and capsular contracture, regardless of patient number (RR 0.41, 95% CI 0.27-0.63, p = 0.18) or total number of procedures (RR 1.29, 95% CI 0.73-2.28, p < 0.01). Current evidence revealed that both systemic and topical antibiotic prophylaxis may not provide benefits in preventing capsular contracture in prosthesis-based breast surgery. When the occurrence of surgical-site infections is minimized to the greatest extent, the administration of additional antibiotics for reducing capsular contracture should be carefully and judiciously considered.

The application and progress of stem cells in auricular cartilage regeneration: a systematic review.

Background: The treatment of microtia or acquired ear deformities by surgery is a significant challenge for plastic and ENT surgeons; one of the most difficult points is constructing the scaffold for auricular reconstruction. As a type of cell with multiple differentiation potentials, stem cells play an essential role in the construction of cartilage scaffolds, and therefore have received widespread attention in ear reconstructive research. Methods: A literature search was conducted for peer-reviewed articles between 2005 and 2023 with the following keywords: stem cells; auricular cartilage; ear cartilage; conchal cartilage; auricular reconstruction, regeneration, and reparation of chondrocytes; tissue engineering in the following databases: PubMed, MEDLINE, Cochrane, and Ovid. Results: Thirty-three research articles were finally selected and their main characteristics were summarized. Adipose-derived stem cells (ADSCs), bone marrow mesenchymal stem cells (BMMSCs), perichondrial stem/progenitor cells (PPCs), and cartilage stem/progenitor cells (CSPCs) were mainly used in chondrocyte regeneration. Injecting the stem cells into the cartilage niche directly, co-culturing the stem cells with the auricular cartilage cells, and inducing the cells in the chondrogenic medium in vitro were the main methods that have been demonstrated in the studies. The chondrogenic ability of these cells was observed in vitro, and they also maintained good elasticity and morphology after implantation in vivo for a period of time. Conclusion: ADSC, BMMSC, PPC, and CSPC were the main stem cells that have been researched in craniofacial cartilage reconstruction, the regenerative cartilage performed highly similar to normal cartilage, and the test of AGA and type II collagen content also proved the cartilage property of the neo-cartilage. However, stem cell reconstruction of the auricle is still in the initial stage of animal experiments, transplantation with such scaffolds in large animals is still lacking, and there is still a long way to go.

Recent progress and clinical applications of advanced biomaterials in cosmetic surgery.

Materials of different allogeneic or xenogeneic or autologous origins are widely used as soft-tissue fillers or structural scaffolds in the field of cosmetic surgery, while complications including prosthesis infection, donor site deformity and filler embolization have always been difficult problems for plastic surgeons. The application of novel biomaterials may bring in hopeful solutions for these problems. Recently, some advanced biomaterials, such as regenerative biomaterials can effectively promote the repair of defective tissues, which have been proven to have good therapeutic as well as cosmetic effects in cosmetic surgery. Therefore, biomaterials with active compounds have drawn significant attention for the tissue regeneration of reconstructive and esthetic treatment. Some of these applications have achieved better clinical outcomes than traditional biological materials. This review summarized recent progress and clinical applications of advanced biomaterials in cosmetic surgery.

In situ photo-crosslinked adhesive hydrogel loaded with mesenchymal stem cell-derived extracellular vesicles promotes diabetic wound healing.

The delayed healing of diabetic wounds is directly affected by the disturbance of wound microenvironment, resulting from persistent inflammation, insufficient angiogenesis, and impaired cell functions. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) showed considerable therapeutic potential in diabetic wound healing. However, the low retention rate of MSC-EVs at wound sites hampers their efficacy. For skin wounds exposed to the outer environment, using a hydrogel with tissue adhesiveness under a moist wound condition is a promising strategy for wound healing. In this study, we modified methacryloyl-modified gelatin (GelMA) hydrogel with catechol motifs of dopamine to fabricate a GelMA-dopamine hydrogel. EVs isolated from MSCs were applied in the synthesized GelMA-dopamine hydrogel to prepare a GelMA-dopamine-EV hydrogel. The results demonstrated that the newly formed GelMA-dopamine hydrogel possessed improved properties of softness, adhesiveness, and absorptive capacity, as well as high biocompatibility in the working concentration (15% w/v). In addition, MSC-EVs were verified to promote cell migration and angiogenesis in vitro. In the skin wound model of diabetic rats, the GelMA-dopamine-EV hydrogel exerted prominent wound healing efficacy estimated by collagen deposition, skin appendage regeneration, and the expression of IL-6, CD31, and TGF-ß. In conclusion, this combination of MSC-EVs and the modified hydrogel not only accelerates wound closure but also promotes skin structure normalization by rescuing the homeostasis of the healing microenvironment of diabetic wounds, which provides a potential approach for the treatment of diabetic wounds.

Prevalence of Merkel Cell Polyomavirus in Normal and Lesional Skin: A Systematic Review and Meta-Analysis.

The prevalence of Merkel cell polyomavirus(MCPyV) in Merkel cell carcinoma(MCC) and non-MCC skin lesions and its possible role in the etiology of other skin diseases remain controversial. To systematically assess the association between MCPyV infection and MCC, non-MCC skin lesions, and normal skin. For this systematic review and meta-analysis, a comprehensive search for eligible studies was conducted using Medline Ovid, Pubmed, Web of Science, and the Cochrane CENTRAL databases until August 2021; references were searched to identify additional studies. Observational studies that investigated the association between MCPyV infection and MCC, non-MCC skin lesions, and normal skin using polymerase chain reaction(PCR) as a detection method and provided sufficient data to calculate the prevalence of MCPyV positivity. A total of 50 articles were included in the study after exclusion criteria were applied. Two reviewers independently reviewed and assessed the eligibility of the studies, and all disagreements were resolved by consensus. To determine the association between MCPyV and MCC, overall odds ratio (OR) were calculated with 95% CI using a random-effects model. Single-arm meta-analyses were performed to examine the prevalence rate of MCPyV+ in MCC, non-MCC skin lesions, and normal skin. The primary analysis was the prevalence rate of MCPyV+ in MCC. Secondary outcomes included the prevalence rate of MCPyV+ in non-MCC skin lesions and normal skin. A total of 50 studies involving 5428 patients were reviewed based on our inclusion and exclusion criteria. Compared with the control group, MCPyV infection was significantly associated with MCC (OR = 3.51, 95% CI = 2.96 - 4.05). The global prevalence of MCPyV+ in MCC, melanoma, squamous cell carcinoma, basal cell carcinoma, Bowen's disease, actinic keratosis, keratoacanthoma, seborrheic keratosis, and normal skin was 80%, 4%, 15%, 15%, 21%, 6%, 20%, 10%, and 11%, respectively. The current results suggest that MCPyV infection is significantly associated with an increased risk of MCC. However, the low prevalence rate of MCPyV+ in non-MCC skin lesions does not exclude a pathogenic association of this virus with the development of non-MCC skin lesions.

Abdominoplasty with Scarpa Fascia Preservation: A Systematic Review and Meta-analysis.

BACKGROUND: Scarpa fascia preservation has been proposed to minimize complications associated with conventional abdominoplasty, but its efficacy is unclear. The purpose of this article is to determine the influence of preserving scarpa fascia on reducing postabdominoplasty complications. METHODS: A comprehensive search of Medline Ovid, PubMed, Web of Science, and the Cochrane CENTRAL databases was conducted from the inception till June 2021. Eligible studies were prospective controlled studies investigating postoperative complications after scarpa fascia preservation following abdominoplasty. Stata 15.1 software was used for the meta-analysis. RESULTS: The meta-analysis included seven studies with 682 abdominoplasty patients. Abdominoplasty with scarpa fascia preservation could significantly reduce incidence of seroma (OR = - 1.34, 95% CI = - 2.09 - - 0.59, P < 0.05), length of hospital stay (SMD = - 1.65; 95% CI = - 3.50-0.20; P = 0.08), time to drain removal (SMD = - 3.64; 95% CI = - 5.76 - - 1.52; P < 0.05), and total drain output (SMD = - 401.60; 95% CI = - 593.75 - - 209.44; P < 0.05) compared with that of conventional abdominoplasty. However, it failed to achieve a statistically significant reduction in hematoma (OR=- 1.30, 95% CI = - 2.79-0.18, P = 0.08), infection (OR = - 1.03; 95% CI = - 2.17-0.12; P = 0.08), skin necrosis (OR = 0.63; 95% CI = - 1.20-2.45; P = 0.50), and wound dehiscence (OR = 0.28; 95% CI = - 0.28-0.83; P = 0.33). The seroma incidence rate was lower when a scalpel was utilized for dissection rather than electrocautery (3% (95% CI = 1-7%) versus 11% (95% CI = 5-18%)). CONCLUSIONS: Preservation of scarpa fascia during abdominoplasty might reduce the likelihood of postoperative seroma, length of hospital stay, time to drain removal, and total drain output. However, it did not significantly affect the incidence of hematoma, infection, skin necrosis, and wound dehiscence. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Translation, cross-cultural adaptation and validation of the Mandarin version of the BDDQ-AS for rhinoplasty patients.

BACKGROUND: The BDDQ-AS (Body Dysmorphic Disorder Questionnaire-Aesthetic Surgery) is a simple and reliable patient-reported outcome measure. It can be used as a screening tool for body dysmorphic disorder (BDD) in patients undergoing aesthetic rhinoplasty. The aim of this study was to translate and culturally adapt the Mandarin version of the BDDQ-AS (M-BDDQ-AS) and evaluate its selected psychometric validation in patients after rhinoplasty. METHOD: According to international guidelines, the BDDQ-AS questionnaire was translated from English to Mandarin. Twenty Mandarin-speaking rhinoplasty patients were interviewed in order to evaluate the understandability and acceptability of the translation and produce a final version. It was then administered to 137 patients with a mean age of 38.75 ± 6.24 years. Psychometric validation were evaluated using reliability (internal consistency, test-retest reliability) and item-reponse theory (IRT) test. RESULT: High internal consistency of 0.823 was found using Cronbach's α coefficient. Reliability of the M-BDDQ-AS resulted in Intraclass Correlation Coefficient (ICC) = 0.863. Besides, based on IRT analysis, the discrimination abilities of all the items were good (over 2.0), and their difficulty estimates were reasonable. CONCLUSION: The M-BDDQ-AS is a reliable and valid self-reported questionnaire that can be used in rhinoplasty patients. The very good psychometric validation of the M-BDDQ-AS indicates that it can be used in clinical practice and scientific research.

Chondrocyte-laden GelMA hydrogel combined with 3D printed PLA scaffolds for auricle regeneration.

The current gold standard for auricular reconstruction after microtia or ear trauma is the autologous cartilage graft with an autologous skin flap overlay. Harvesting autologous cartilage requires an additional surgery that may result in donor area complications. In addition, autologous cartilage is limited and the auricular reconstruction requires complex sculpting, which requires excellent clinical skill and is very time consuming. This work explores the use of 3D printing technology to fabricate bioactive artificial auricular cartilage using chondrocyte-laden gelatin methacrylate (GelMA) and polylactic acid (PLA) for auricle reconstruction. In this study, chondrocytes were loaded within GelMA hydrogel and combined with the 3D-printed PLA scaffolds to biomimetic the biological mechanical properties and personalized shape. The printing accuracy personalized scaffolds, biomechanics and chondrocyte viability and biofunction of artificial auricle have been studied. It was found that chondrocytes were fixed in the PLA auricle scaffolds via GelMA hydrogels and exhibited good proliferative properties and cellular activity. In addition, new chondrocytes and chondrogenic matrix, as well as type II collagen were observed after 8 weeks of implantation. At the same time, the transplanted auricle complex kept full and delicate auricle shape. This study demonstrates the potential of using 3D printing technology to construct in vitro living auricle tissue. It shows a great prospect in the clinical application of auricle regeneration.

HNRNPA1-mediated exosomal sorting of miR-483-5p out of renal tubular epithelial cells promotes the progression of diabetic nephropathy-induced renal interstitial fibrosis.

Diabetic nephropathy (DN) is a serious complication in type 1 and type 2 diabetes, and renal interstitial fibrosis plays a key role in DN progression. Here, we aimed to probe into the role and potential mechanism of miR-483-5p in DN-induced renal interstitial fibrosis. In this study, we corroborated that miR-483-5p expression was lessened in type 1 and type 2 diabetic mice kidney tissues and high glucose (HG)-stimulated tubular epithelial cells (TECs), and raised in the exosomes derived from renal tissues in type 1 and type 2 diabetic mice. miR-483-5p restrained the expressions of fibrosis-related genes in vitro and renal interstitial fibrosis in vivo. Mechanistically, miR-483-5p bound both TIMP2 and MAPK1, and TIMP2 and MAPK1 were bound up with the regulation of miR-483-5p on renal TECs under HG conditions. Importantly, HNRNPA1-mediated exosomal sorting transported cellular miR-483-5p out of TECs into the urine. Our results expounded that HNRNPA1-mediated exosomal sorting transported cellular miR-483-5p out of TECs into the urine, thus lessening the restraint of cellular miR-483-5p on MAPK1 and TIMP2 mRNAs, and ultimately boosting extracellular matrix deposition and the progression of DN-induced renal interstitial fibrosis.

Preparation and application of chitosan biomaterials in dentistry.

Chitosan is a biodegradable and biocompatible natural polysaccharide that has a wide range of applications in the field of dentistry due to its functional versatility and ease of access. Recent studies find that chitosan and its derivatives can be embedded in materials for dental adhesives, barrier membranes, bone replacement, tissue regeneration, and antimicrobial agent to better manage oral diseases. In this paper, we provide a comprehensive overview on the preparation, applications, and major breakthroughs of chitosan biomaterials. Furthermore, incorporation of chitosan additives for the modification and improvement of dental materials has been discussed in depth to promote more advanced chitosan-related research in the future.

Modified Use of Costal Cartilage in Asians for the Correction of Nostril Asymmetry in Unilateral Secondary Cleft Lip Nasal Deformity.

BACKGROUND: Weak alar cartilage and lack of soft tissue on the cleft side are considered to be the main critical factors leading to the asymmetry of bilateral nostrils. The costal cartilage can provide strong structural support and can be used to maintain long-term stability of nostril shape after surgical correction. With the advancement in rhinoplasty techniques, the application and understanding of costal cartilage in cleft lip nasal deformity is still on going. Herein, we present our technique of applying costal cartilage to provide nostril support and correct asymmetry in Asian patients with unilateral secondary cleft lip nasal deformity. METHODS: Ninety-seven patients who underwent nostril asymmetry correction from January 1, 2013, to October 31, 2018, were analyzed retrospectively. Modified integrative alar cartilage strut and diced nostril augmentation with costal cartilage were implemented to improve the collapsed and flat cleft-side nostril. The release and restoration of muscle and bone were also performed when required. Surgical outcomes were analyzed based on the comparison of nostril parameters, the shape and contour, and symmetry of bilateral nostrils after surgery. During postoperative follow-up, the patients' satisfactions with the corrective outcomes were also investigated. RESULTS: All patients received the corrective operations with complete survival of all implanted cartilages. The nostril width was narrower in postoperative group (P < 0.05). The nostril height and long axis angle were higher postoperatively (P < 0.05). After correction, the proportion of moderate type increased from 13.4% to 80.4%, whereas the proportion of horizontal type decreased from 86.6% to 17.5%. The symmetry score on the nostril parameters manifested the rate of high score (AS >3) in postoperative groups were 84.5%, 93.8%, and 87.6% for width, height, and angle of the long axis, respectively. They were higher compared with those of preoperative group (0%). More than 95% of the patients were satisfied with the overall aesthetic outcome of the surgery. CONCLUSIONS: Through ameliorating its constructive technology and optimizing its filling form, the modified use of costal cartilage displayed excellent correction effects in the width, height, and long axis angle asymmetry of Asian patients' nostril. Precise and comprehensive rhinoplasty technique is the cornerstone for achieving satisfactory long-term aesthetic outcomes, especially in severe cases, such as secondary cleft lip nasal deformity.

Repair of severe traumatic nasal alar defects with combined pedicled flap and conchal cartilage composite grafts: a retrospective study.

BACKGROUND: Repair of traumatic alar defect is challenging because poor blood supply is caused by contracture scars, which sometimes extend beyond the alar groove. However, few studies have investigated the reconstruction results of severe traumatic cases. This study aimed to examine the clinical outcomes of severe traumatic alar defect reconstruction using either pedicled nasolabial or forehead flaps combined with conchal cartilage. METHODS: This retrospective study investigated the clinical characteristics and treatment effects of 17 patients with severe traumatic alar defects treated in a single plastic surgery center from March 1, 2015, to September 1, 2018. All cases were scored and graded with regard to the size and depth of the alar defect and the surrounding scar according to the Alar Defect Severity Score (ADSS). Surgical outcomes were evaluated on the basis of the severity of defect before repair, donor site distortion, and postoperative nasal symmetry, especially shape and color. RESULTS: The average ADSS of the cases was 8.1±0.8 (highest score, 9.0). No flap necrosis or any complications were observed postoperatively. The symmetry of the bilateral alae was satisfactory. No color distinction between grafts and surrounding tissues, retraction, or inferior displacement of the ala was observed at an average follow-up of 24.2±10.4 months (range, 8-42 months). The average postoperative surgeon-based evaluation score was 4.3±0.2 (highest score, 5.0). Esthetic and functional results were satisfactory in all cases. CONCLUSIONS: A pedicled flap combined with conchal composite grafts should be considered for the treatment of severe traumatic alar defect. This is a reproducible technique that enables a predictably decent outcome for severe traumatic alar defect, especially in Asian patients.

Review of Plastic Surgery Biomaterials and Current Progress in Their 3D Manufacturing Technology.

Plastic surgery is a broad field, including maxillofacial surgery, skin flaps and grafts, liposuction and body contouring, breast surgery, and facial cosmetic procedures. Due to the requirements of plastic surgery for the biological safety of materials, biomaterials are widely used because of its superior biocompatibility and biodegradability. Currently, there are many kinds of biomaterials clinically used in plastic surgery and their applications are diverse. Moreover, with the rise of three-dimensional printing technology in recent years, the macroscopically more precise and personalized bio-scaffolding materials with microporous structure have made good progress, which is thought to bring new development to biomaterials. Therefore, in this paper, we reviewed the plastic surgery biomaterials and current progress in their 3D manufacturing technology.

High-sensitivity gas pressure sensor based on a multimode interferometer using hollow-core tube lattice fiber.

A non-diaphragm fiber gas pressure sensor based on a multimode interferometer (MI) using a hollow-core tube lattice fiber (HC-TLF) as a gas cell is proposed and experimentally demonstrated. The sensor is fabricated by fusion splicing a sandwich structure of a graded-index multimode fiber, HC-TLF, and lead-in/out single mode fiber. Several side-holes are drilled by using a femtosecond laser on the side wall of the HC-TLF to allow gas in and out of the fiber. The positions of side-hole in HC-TLF have been investigated during the experiments, which indicate that the highest gas pressure sensitivity existed as the side-hole located in the gap between adjacent cladding holes of the HC-TLF. The proposed structure exhibits a high sensitivity of 8.1 nm/MPa with the average gas fill time of 2.2 s. This sensor also has low temperature sensitivity and low temperature cross sensitivity of 12.3 pm/°C and 1.5 kPa/°C as the temperature rises to 400°C. In addition, the advantages of the gas pressure sensor, such as small size, rapid response, low temperature cross sensitivity, and simple fabrication process, make it suitable for high-pressure measurement in harsh conditions, e.g., downhole and ocean bottom.

MiR-21 Regulates Keloid Formation by Downregulating Smad7 via the TGF-ß/Smad Signaling Pathway.

A keloid is a benign fibroproliferative skin tumor that results from abnormal wound healing after injury and tends to grow beyond the boundary of the original wound; the mechanism of keloid formation is still unclear. MicroRNA-21 (MiR-21) is a representative microRNA that plays a key role in a variety of fibrotic diseases via the transforming growth factor-ß/Smad signaling pathway. The aim of our study was to explore the mechanism of keloid formation. First, we found that the expression of miR-21 in keloids and keloid fibroblasts was significantly upregulated by microRNA microarray and real-time polymerase chain reaction. Additionally, at the protein level, our study confirmed that the overexpression of miR-21 could promote the process of keloid fibrosis to some extent and also indicated that a low expression of miR-21 could inhibit the process of keloid fibrosis. Finally, the results proved that miR-21 could participate in the keloid fibrosis process through negative regulation of its downstream target gene Smad7 via the transforming growth factor-ß/Smad signaling pathway, which provides a guiding framework for further studies and new theoretical support for keloid clinical treatment.

[Application of three-dimensional mechanical equilibrium concept in cartilage scaffold construction for total auricular reconstruction].

Objective: To summarize clinical experience and curative effect in applying three-dimensional mechanical equilibrium concept to cartilage scaffold construction in total auricular reconstruction. Methods: Between June 2015 and June 2017, ninety-seven microtia patients (102 ears) were treated with total ear reconstruction by using tissue expanders. The patients included 43 males and 54 females and their age ranged from 7 to 45 years with an average of 14 years. There were 92 unilateral cases (45 in left side and 47 in right side) and 5 bilateral ones. There were 89 congenital cases and 8 secondary cases. According to microtia classification criteria, there were 21 cases of type Ⅱ, 67 cases of type Ⅲ, and 9 cases of type Ⅳ. Tissue expander was implanted in the first stage. In the second stage, autogenous cartilage was used to construct scaffolds which were covered by enlarged flap. According to the three-dimensional mechanical equilibrium concept, the stable ear scaffold was supported by the scaffolds base, the junction of helix and inferior crura of antihelix, and helix rim. The reconstructed ears were repaired in the third stage operation. Results: All patients had undergone ear reconstruction successfully and all incisions healed well. No infection, subcutaneous effusion, or hemorrhage occurred after operation. All skin flaps, grafts, and ear scaffolds survived completely. All patients received 5- to 17-month follow-up time (mean, 11.3 months) and follow-up time was more than 12 months in 61 cases (64 ears). All reconstructed ears stood upright, and subunits structure and sensory localization of reconstructed ears were clear, and the position, shape, size, and height of bilateral ears were basically symmetrical. Mastoid region scar hyperplasia occurred in 3 patients, which was relieved by anti-scar drugs injection. No scaffolds exposure, absorption, or structural deformation occurred during follow-up period. Conclusion: Application of three-dimensional mechanical equilibrium concept in cartilage scaffold construction can reduce the dosage of costal cartilage, obtain more stable scaffold, and acquire better aesthetic outcomes.

Label-free detection of bovine serum albumin based on an in-fiber Mach-Zehnder interferometric biosensor.

We propose and experimentally verify an innovative label-free optical fiber biosensor based on a Mach-Zehnder interferometer for bovine serum albumin (BSA) concentration detection. The proposed fiber biosensor utilized a micro-cavity within a single-mode fiber to induce Mach-Zehnder interference. A remarkable feature of this biosensor is that external media can directly interact with the fiber core signal through microfluidic channels connected to the micro-cavity and sensor surface. The device was fabricated by means of femtosecond laser micromachining and chemical etching. A fiber interferometer of this type exhibits an ultrahigh refractive index sensitivity of -10,055 nm/RIU and a detection limit of 3.5 × 10-5 RIU. Different concentrations of BSA with an infinitesimally small refractive index difference can be clearly differentiated in situ by the interferential spectra of the structure. Experiments demonstrated the biosensor exhibited a BSA solution concentration sensitivity of -38.9 nm/(mg/mL) and a detection limit of 2.57 × 10-4 mg/mL, respectively. Moreover, this biosensor is a sub-microliter dose and ultrasensitive at the low concentrations detected in BSA, which make it a promising for biochemical applications such as DNA hybridization, cancer screenings, medicine examination and environmental engineering, etc.